Durham and Newcastle, 1975-1991

Allan Seheult (Durham)

Julian was appointed in 1975 to the established Readership in Statistics at Durham University and eventually to a newly established Chair in Statistics. During this period, Peter Green, Chris Jennison, Bruce Porteous, Nick Fay and Ian McPhee were appointed to Lectureships, Stephen Duffy and Richard Hayes to Temporary Lectureships, while I had been there since 1970. He left Durham in 1989 for Seattle.

Nick Fay had been at a very difficult school in a rough area of Newcastle. Nick used to refer to himself as the 'YTS boy'. Julian, demonstrating his thoughtful and caring qualities, wrote to Nick's headmaster to tell him about the appointment and received a very appreciative response. Sadly, Nick died at a young age of multiple sclerosis.

Julian arrived at Durham from a research post at Princeton, enthusiastic about John Tukey's Exploratory Data Analysis and its implementation in APL. This was quite distinct from his seminal work in spatial statistics, so much so that when he gave talks on EDA at a joint applied probability and geography meeting in Bristol and later at the Royal Statistical Society conference in Oxford he worried about his reputation as an applied probabilist. However, interest in EDA and computing illustrated the importance of the analysis of real data to his whole approach to statistics. EDA became a distinctive feature of statistics courses at Durham, possibly the first such implementation in the UK.

Julian's research is well documented, but his applications of spatial modelling to image analysis, agricultural field trials, disease mapping and the significance of proximity of cancer cases to nuclear reactors were initiated while he was at Durham. Markov chain Monte Carlo methods, which he developed in the context of image analysis, were always a sensitive issue for Julian, as he was always very careful to acknowledge and give credit to the work of others. As with MCMC, his work on Monte Carlo significance tests, while initially developed in a spatial context, turned out to have much wider applications.

Julian was passionate about research and very supportive of the work of staff and students at Durham. There is no doubt he had a significant influence on the research careers of Peter, Chris, Bruce, Stephen and myself. He was an RSS enthusiast, a member of its Research Section, and encouraged discussion contributions and regular attendance at meetings; and his brinkmanship which involved almost missing trains back from London was a distinctive feature of these trips!

Then of course there was lunchtime running, where research, teaching and departmental issues were discussed. It was sometimes suggested that you couldn't get appointed to a statistics post at Durham unless you had running on your CV!

Julian also cared passionately about teaching. His notes were meticulous. However, a lecture in which he introduced robust regression didn't go well. To offset his disappointment, he produced a carefully written, detailed, printed version which he made available to the students the very next morning.

Julian instigated computer practicals, written in APL, which centred on EDA, simulation and Monte Carlo significance tests mostly for analysis of variance. He was concerned about the dearth of statistics courses available to undergraduate mathematicians and succeeded in getting the Board of Studies to agree to a final-year double option in statistics. He wrote the syllabus and delivered the course, which included statistical analysis practicals, unlike the mostly theoretical third-year statistics option it replaced.

Julian's examination questions and solutions were always very carefully written, making the checker's work a simple task. There was often a humorous or politically inspired twist to a question. One such question involved three chimpanzees breaking a twig and then calculating the probability that the three parts formed a triangle. The names of the chimpanzees were italicised Greek transliterations of the first names of the three department professors! The external examiner did not comment.

A number of contributors have commented in their reminiscences on Julian's sometimes difficult, abrasive manner, which often resulted in his falling out with those closest to him. These aspects of his complex character apart, Julian was passionate about statistics, hockey and life. He was punctual, very hard working (early to work and late to leave), exacting, always honest with his research, which he wrote up in meticulous, tight prose.

Julian confronted things head on, spoke his mind, rarely shirking the possibility of any resulting difficult conflict. After a talk by Stephan Morgenthaler to a research student conference in Durham a few years ago, Julian started the subsequent discussion by remarking that "there were so many things wrong with the talk, he didn't really know where to start", but he did anyway. Fortunately, Stephan didn't take it personally but dispassionately addressed the issues Julian had raised.

At a social level, Julian could be either up or down, either centre-stage or in the background. On many occasions after parties at their house, when Julian would consume a fair amount of alcohol, Valerie would telephone guests the next day to apologise just in case Julian had been rude to them!

I remember with great affection a lunch with Julian at the New Inn when, after having hamburger and chips, a packet of salted peanuts, a Mars bar and of course at least one pint, he suggested we repeat the menu, which we did; and then we repeated it a third time! After these excesses, we walked back to his house for tea and cheese sandwiches! Needless to say, both of us were a little the worse for wear.

At a personal level, it was a privilege to work with Julian. It was a result of his influence that I had a twenty-year inspirational collaboration with John Tukey on robust analysis of variance. Also, my contributions to image analysis and agricultural field trials were a direct consequence of Julian's ground-breaking research in these areas.

Julian Besag was a great statistician. He will be sadly missed.

Julian Wolfram (Falmouth)

I'm perhaps unusual amongst you as I met Julian through a baby-sitting circle. This was shortly after he arrived in Durham in the mid-seventies. However we did have a common interest - pubs, beer and wine.

Although I'm not a statistician I was beginning to use some statistics in my work and ad hoc conversations with Julian in the New Inn, Half Moon, Colpitts, Rose Tree and Dun Cow gave me insight into a range of techniques including exploratory data analysis, robust regression and the jack-knife - never mentioned in my physics undergraduate stats course. As long as I kept my brain in gear I found him an excellent, informal tutor - let your brain slip out of gear and he could get pretty pissed off. He set the highest standards and could be brutally honest. I remember, later, asking if he could recommend a statistician to consult at the university I was then at - the phone went quiet for a minute and then he said 'No'. Same thing when I asked to recommend a good fish restaurant in Seattle.

Anyway, it is largely down to Julian that I've used stats frequently, and more rigorously, in my research over the last thirty-odd years and I will always remain indebted to him.

Julian also introduced me to mixed hockey. I should have known what to expect when he told me it was a strict rule - no glasses, cans or bottles on the pitch. Julian was pretty good at hockey then - at 30, and with a pigeon-toed gait, not the quickest on the pitch but very determined and quite aggressive. To reciprocate I invited him sailing. I remember in particular an overnight race along the North Sea coast down to Whitby. It started well enough with a gentle, warm offshore wind and he sat happily with the rest of the crew on the weather deck with his feet hanging over the side and a can of beer in his hand. The weather soon changed, the wind swung around onto the nose, the sea got up and the moonlight disappeared as the clouds came over. As the shout "ready about" came the cans were jettisoned and the crew ran across the deck. As the boat heeled the other way Julian was still struggling to get topsides, dragging himself up with one hand as he was determined to hang on to his beer. The beer soon ran out and we the spent the next 5 hours beating into a cold North sea - the sort of thing that puts people off sailing for life!

Not long after this I moved from Durham and had little contact with Julian until I went to a conference in Seattle and Julian met me at the airport with a Jaguar sports car and, to my surprise, whisked me off to see his boat - a very nice forty-four foot sailing boat. So he hadn't been put off sailing, and he lived in a house-boat!

He was a little disappointed that, apart from giving my own paper, I was actually planning to attend other sessions. He explained what you should do is present your paper, ideally as the keynote speaker, say hello to everyone and join them for lunch and then quietly slip away. As the weather was good, after a day and a bit at the conference I followed his advice and we spent a couple of days sailing around the Puget Sound, drinking Burgundy and beer and discussing what was wrong with the world. I was alarmed when we brushed against a large whale but Julian wasn't in the least perturbed. He was in good form and fascinating to listen to. We really enjoyed our sail and started to plan a longer, future trip up to Canada - it never happened.

I'll remember him as a demanding friend who could be great company, a brilliant statistician and a not half bad sailor.

Liz Green (Bristol)

I am not a statistician, so this is a personal note.

I first met Julian and Peter Diggle on the same occasion, at Allan Seheult's house in Durham. It was a long time ago, possibly early in 1975, before Julian came to Durham, and when the only Peter Green I had heard of was a guitarist. In Durham I remember Julian as a regular lunchtime runner with other members of the maths department, to keep himself fit for hockey which he played to a serious standard. I remember that he fought vigorously and vehemently for the third chair in maths to go to statistics, rather than alternate between pure and applied, so it was probably only fair that he was the first professor of statistics at the University of Durham.

One summer Peter and I visited Seattle and sailed in at least two of his many boats. Julian loved the water and lived in a houseboat. Peter took me out in a tiny dinghy across Lake Union, which I found terrifying and did a lot of bailing out, but later during that trip we had a great adventure on Julian's yacht, sailing under the bridge and away into the ocean, drinking beer in the sunshine. This was a wonderful experience which stays with me.

It was sad to see Julian's physical strength leave him in his last years. At first, he was frustrated by some of the technology that would make it easier for him to enjoy living in his flat in Bristol, but eventually he got the hang of it and at long last he discovered internet shopping. This was a huge breakthrough and saved us all many frustrating expeditions to Sainsbury's. Julian was not a good shopper and hated every minute of it.

Peter and I visited him when we could while he was in hospital here and saw him the day before he died. He knew he was dying but was very clear on some points and not in pain. The nursing staff was kind and caring and he was in good hands. We are sorry we could not attend Julian's funeral, so I am pleased to have this opportunity to contribute in his memory.

Julian was a huge, larger than life character and the scientific community must mourn his loss. We must take people as we find them. Whilst Julian could be very tetchy, through pain or frustration, and I know he upset many people with his brusque manner, to me he was always kind and courteous and this is how I shall remember him.

Anonymous

Julian, I disappointed you many years ago, and I'm doing so again now as I am sure you would expect me to be at this meeting. As before, I have modest excuses, but again they would not satisfy you.

We met and communicated quite a lot for a couple of years, and then intermittently for several more years. Our interests diverged, and after 1988 I only saw you twice, very briefly - once in 1992, and lastly in 2000. We had a brief e-mail correspondence in 2004, when you said "All the very best for the future". I didn't hear from you again.

We were never very close - I didn't share any of your other interests. Although I could never be sure how I would find you, the generous you far outweighed the grumpy you (and usually I sympathised).

I am grateful to you for many things, and I have always appreciated your early regard. You were a great inspiration to me, and, although we hadn't been in recent contact, I feel a huge loss that you are gone.

I would like to finish with some (slightly adapted) words of Tom Paxton, which seem very appropriate to me:

Are you going away with no word of farewell?
Will there be not a trace left behind?
I could have served you better - didn't mean to be unkind,
you know that was the last thing on my mind.

Goodbye Julian, I miss you.

Peter Green (Bristol)

I first encountered Julian in 1972, during a seminar in Manchester. Ten minutes into the talk there was a commotion, and two young men came in. One might have been Peter Diggle, but the other one clearly stuck in my memory by reminding me, by his features and air of bravado, of Alex, the protagonist in the Clockwork Orange. I learnt that this was Julian, and I first met him properly, along with Denis Mollison, on a mountain walk in the Vercours in 1976.

A few years later, a lectureship was advertised in Durham. I was ready for a change and applied and, in spite of a terrible interview under the influence of the excellent pre-interview hospitality from Julian and Allan Seheult, got the job. Thus, in 1978 began a roller-coaster 11 years that changed my life. Looking back, it seems that everything I now know in statistics I learned then, from Allan, Julian and, later, Chris Jennison. In research, Julian influenced everything I did from then on, and which has given me a fortunate and happy career, one that he supported and encouraged in many ways.

It was tremendously exciting to witness a bumpy but very productive stage of Julian's career. Julian's attitude to me was complicated, but I think my main role was as a sounding-board for his ideas. He would come into my office with a stream of consciousness about his current preoccupation, not I think to show off, but to practise explanations, and often to seek reassurance. He was very insecure about his lack of formal mathematical training and he hoped that I would somehow authenticate his ideas. In reality, although I sometimes found a useful counter-example, and occasionally made a more positive contribution, almost always he was right and I simply agreed. His intuition was outstanding; he always repudiated any suggestion that he had mathematical ability, and while it's true that he was never going to submit to the Annals, I maintain my belief that he had very deep understanding, as well as great perception and originality.

18 years after we both left Durham, Julian returned to my neighbourhood in 2007, to his post in Bath. We encouraged him to visit the group here in Bristol, and to the extent his poor health allowed, he did so, driving over in his glamorous Mercedes cabriolet. For many months between December 2008 and October 2009 he was in hospital in Bristol, and I tried to see him regularly. Ultimately he was discharged, basically for refusing the radical treatment recommended for his infected feet. He had come to like being in hospital, and rather dependent on it, and we were concerned and sceptical how well he would thrive living on his own. But he did remarkably well, and in some ways his last months were rather contented, although lonely. He had a wonderful rented apartment right on the harbour-side in Bristol, just half a mile from here. There he would look out at the sailboats and other activity on the water and the banks, and in spring he took an intense interest in the fortunes of the fledgling ducks.

Julian's last public appearance was here in the Orangery at Goldney, at one of our research workshops. He was not actually supposed to be on the programme. At the end of the keynote lecture on day 1 of the meeting, he challenged the speaker rather bluntly, on the grounds that the exponential family random graph model presented did not actually fit the phenomena in social networks that was claimed. This challenge went unanswered, and in the coffee break that followed Julian offered to give a talk on exact p-values for networks, and this he did on 1st July 2010.

At the end of the month, however, his condition worsened and he was readmitted to hospital, where, too little and too late, he had his operation, and died within 2 weeks. He had until his last couple of weeks been optimistic, and was on the brink of exchanging contracts to buy a bigger flat in the same block, one with an even better view over the harbour.

Robin K. Milne (Perth)

I first met Julian at the University of Western Australia during a visit of a few weeks that he made here early in 1976 at the invitation of Terry Speed. Julian gave several seminars and a very interesting short lecture course on spatial processes to our honours class of that year, based largely on the content of his JRSS B (1974) paper. That class was, incidentally, the largest and perhaps best honours class in statistics of all my 37 years in Perth, whilst Terry Speed, Mike Thornett and I were amongst others who also formed a part of Julian's audience.

I did spend considerable time with Julian during that visit, in particular because he made it clear that he would welcome the company. I can remember vividly one colourful evening when Julian and I demolished a significant portion of a flagon of port, which Julian had decided was his drink of choice for that evening. We had a very pleasant evening, but that experience taught me that I did not have quite the same resilience as Julian!

Early in 1980 I spent about five weeks in the Durham-Newcastle area, visiting especially Julian. He was very hospitable, inviting me to stay initially at his house and insisting on personally cooking what seemed to be his staple meal --steak and chips with green peas! Later he believed that I should be better looked after, and arranged that I would board for the remainder of my stay with his wife Valerie, who by that time was living separately, along with their son David.

Julian decided that my expertise would complement his and that of his research student Stan Zachary, and that I should work with them to write a paper. This became 'Point process limits of lattice processes', published in JAP (1982). To facilitate this work Stan visited Durham during this period and somewhat later in 1980 I visited Stan at Heriot-Watt.

I remember fondly Julian and many others whom I met in the North-East on that visit. In particular I remember Julian for his tremendous mathematical and statistical insight. Despite this, in personal conversation he readily confessed to feeling mathematically ill-equipped to deal with some tasks. In such ways he was disarmingly honest and had an intense dislike of what he usually called 'humbug'. He was direct and sometimes rather confronting in his personal style, yet I think that this directness did earn him lasting respect. I was very sad to hear of his passing, but I am pleased to have the opportunity to contribute these words in his memory.

Mike Titterington (Glasgow)

My contribution takes the form of non-technical reminiscences, while acknowledging the profound and continuing influence that Julian's writings have had over the last close-on four decades.

I first encountered Julian in a bar in Leuven at the European Meeting of Statisticians in 1977. He was rather subdued but, I hasten to add, as a result mainly of jet-lag from Australia rather than of what the bar had to offer. Another warm, indeed weather-wise distinctly hot, European-Meeting memory comes from the 1987 event at Thessaloniki. Julian was on the organising committee and ensured that there were long afternoon breaks to allow for expeditions, by coach, to a suitable beach away from the polluted sea near the city. More personally, I recall a hot but enjoyable walk in the hilly area surrounding the city, with Julian and my colleague, Ben Torsney, during the weekend preceding the Meeting.

I always felt that I got on well with Julian and I recall very generous (possibly misguided!) words from him about things I had written and the occasional milestone that I passed. He always asked kindly after my son, also a David, especially when he discovered that David was learning to sail, a former passion of my own.

Finally, I'd like to mention a particular kindness. A few years ago I sent him a full-page article from the (Glasgow) Herald newspaper, written by Jonathan Raban about sailing in the Puget Sound, near Seattle. I thought no more of it until, some time later, I received in the post from Julian a copy of "Waxwings", which was Raban's latest book based on life in Seattle; the book was signed - by the author! Since then, from time to time I tried, unsuccessfully I'm afraid, to think of an appropriate gesture I could make in return; the last time I wracked my brain about this was on about August 3rd, 2010.

Sheila Bird (Cambridge)

Julian Ernst Besag FRS: ABC and more? - Farewell, friend

Aberdeen, 1978 is where I first met David Andrews, Julian Besag and David Cox, our three guest speakers at a Scottish and Northumbrian Academic Statisticians' meeting.

Bristol is where Julian and I last met: Julian - from his hospital bed - had arranged to take me to lunch at Fishers, not far from the suspension bridge. After lunch, I delayed fetching the car to give me time to pick up literature on flats-for-sale in Bristol (and to buy a birthday present): Julian was furious with me, as he had come out to wait and had waited too long. But the last emails I had from him, around his 65th birthday, included an eloquent description of the harbour view from his flat in Bristol.

In between, Cambridge: where Julian would appear from time to time, usually in a spectacular motor, sometimes unhappily, sometimes mischieviously, sometimes whimsically, often challengingly. Of course, Julian took on challenges himself. Little knowing how much boats and his Union Lake boat-house (as I called it, to irk him) would come to mean to him, I'd challenged Julian to a very cold swim in the North Sea off Durham/Newcastle!

Finally Donation: I had worked on kidney transplantation, "matchability", and the first audit of UK's potential for cadaveric solid organ donation. Julian was a well-informed patient, but I was never quite sure whether he had gone through the procedures to be listed for kidney transplantation, or knew his "matchability". Conversation in hospital turned to a paper on presumed-consent for cadaveric organ donation which I was working on with ethicist Professor John Harris. Both of us as authors were dismayed that the Organ Donor Taskforce had set its face against presumed consent without properly quantifying how many additional kidney, heart, liver, lung transplants there could have been - had the UK's presumption been that organ donation would proceed unless, in life, the deceased had opted-out, or a family over-rode the presumption. This could have benefitted Julian. But - selflessly, righteously and passionately - Julian inveighed agin me to be so unfeeling for the relatives of the deceased, and to be so cavalier as to risk bringing the whole of medical statistics into disrepute. He appealed to Peter Green to avert me from my course, and me not to publish.

I did pay some heed to his reaction, which the British Medical Journal feared its readers might share. After (much) editing, the published paper attracted more correspondence than any other I have been associated with - the majority of correspondents agin it in such phrases as "cold statistics". Sadly, I never gave Julian the satisfaction of telling him how rightly, as well as selflessly, he had anticipated reactions!

In reflective conversations in hospital - often less private than ideal because louder on account of Julian's tinnitus - I heard about unsung good deeds. Only at Julian's funeral, for example, did I realize that he'd never explained to Valerie his principled stand, on being awarded the RSS Guy Medal in Silver, that he would not accept an invitation to celebrate with the Statistical Dining Club because his wife had not been invited. He remained very proud of Valerie's books and of David as local councillor.

Ted Harding (Ely)

I first got to know Julian when he visited Henry Daniels in Cambridge in the late 1970s, where Henry had an office in the Statistical Laboratory following his retirement as Professor of Statistics at Birmingham. The link between Julian and Henry would have gone back to Julian's transition from studying Engineering at Cambridge to studying Statistics at Birmingham in the 1960s. In his own words: "I started off in statistical ecology with MSB[artlett] and initially that interested me (indeed since a first-year undergrad course from David Wishart at Brum)". But, later on: "I quickly realized that statistical modelling had little to offer such a complex subject".

Julian and Henry's discussions, I believe, revolved around merging Julian's original ideas for modelling stochastic processes, especially spatial, and Henry's gifted skills in analytical formalisation of such processes, especially asymptotically. I was invited to join in occasionally, particularly on the computational front.

I was struck by the intensity of interaction between Julian and Henry. While it was not antagonistic, each could be sharply critical of the other's ideas and methods. Julian, in particular, displayed constant intense critical alertness. He would instantly absorb what was being put to him, form a vivid intuition of it, and rapidly throw back the implications of his view. This was also coupled with an ability almost instantaneously to formulate a mathematical expression of his intuition.

These first meetings were the beginning of a long friendship with Julian. Just as with Statistics, friendship for Julian meant intense involvement. Indeed, if he was going to take an interest in anything - whether it were modelling childhood leukemia, pursuing a tangential side-issue (which would unexpectedly lead back to the main topic), sailing, observing nature from his boat, or enjoying a good meal and a very good bottle of wine with a friend - it would involve his whole attention.

After he moved to Seattle, we maintained email contact. He could go for months, or more than a year, without writing; but, when he did, it was always with the same great friendship.

His intuitive side often generated very interesting subjects for thought, sometimes apparently bizarre - until one had seen them develop by arguing about them with him! Shortly after his return from Seattle to Bath in 2007, and a very bad experience with a bout of shingles, he wrote:

"The good news is that I seem to have surfaced in a different place mind-wise and ... I'm positive, am thinking again and coming up with new ideas, in particular on animal behaviour."

"My hypothesis is that some animals possess senses that we simply don't know about but that we can learn about through experimentation. This is exemplified by "Besag's (blind) mole" which performs simple experiments on humans to extract the properties of what we call "sight". Probably not new but quite fun anyway. It has always seemed to me to be arrogant to assume one can explain animal behaviour in human terms: I take my lead from watching the ducks on Lake Union [Seattle] from my house."

This led us into discussing the sorts of senses we might not be aware of, mechanisms that other creatures can exploit but we cannot, e.g. sensing the Earth's magnetic field, or even being able to "see" it, how wasps find their way to the honey-pot (possible odour gradient detection by differential perception in the two antennae, along with their characteristic side-to-side motion while flying up-wind), and so on.

Almost in defiance of his great abilities, Julian could be intensely self-doubting, yet paradoxically exploit his own self-doubt. As he once wrote:

"I've had new ideas because I can't understand what other people do (unless I spend an awfully long time at it). I have absolutely no powers of (conventional) abstraction. There are advantages in having bugger-all knowledge (I've long told my students I do research because I understand so little about what other people do)."

His last few years at Bath were a sad, painful progression to the physical failure of his body, yet borne with a resilient courage. I treasure my memories of his friendship, and of my glimpses of a fascinating personality.

Chris Jennison (Bath)

When I completed my PhD and applied for jobs I was fortunate to be appointed to a lectureship in Durham. There I joined Julian, Allan Seheult and Peter Green. Not having much experience, I assumed this was a normal group of statisticians. I was, of course, in an extraordinarily stimulating environment. In my three years in Durham, Julian introduced me to spatial modelling, Markov random fields, agricultural field trials, Monte Carlo simulation based on Markov chains, and image analysis.

Julian recognised my liking for mathematical puzzles. While he was working on the Rasch model, he posed a problem one day over coffee. Suppose you know the row and column totals of a two-way table of ones and zeros. Given one example of such a table, you can create more examples by taking four cells on the corners of a rectangle containing 0, 1, 1 and 0, then changing the ones to zero and the zeros to one preserves the row and column totals. Will such moves take you to all possible tables with the given row and column totals? I thought for a while and went to the blackboard and outlined a proof that the answer is yes. I realised later that Julian was impressed by this. About ten years on, when I had moved to Bath and Julian to Seattle, we met at the Interface Conference in Michigan and Julian asked me if I could reproduce my proof. By about four o'clock in the morning, I had managed to re-create it: I committed it to paper this time. Another eight years later, when I visited Julian in Seattle he told me "You know your proof for the Rasch model. It's not new. I found a version published in the 1950s."

On that visit to Seattle, Julian took Debbie and me on a two-day sailing trip. At one point, with the sun shining and the wind blowing strongly, he gave Debbie the helm: while she stood terrified as the boat leaned at forty-five degrees, he grinned, knowing there was no danger of capsizing (at least I hope that was the case). Later, we learnt something about Julian's musical tastes while enjoying a drink in a bar. As the live music started up, Julian took out his hearing aid, put it in his pocket and stated "I hate xylophones".

Julian came to Bath in 2007. He took his place in the Department but his health was poor and he was frustrated by how easily he became tired and the difficulty in concentrating on new work. He spent periods in hospital, where he was not the most conventional of patients. On one visit, while I was still taking off my coat and finding a chair Julian picked up a notepad and drew points and triangles. Pointing to the Voronoi tessellation he had just produced, his words of welcome were "What happens to these triangles as this angle goes to zero?"

I never knew what to expect on those visits. We had conversations about work, life, and the world. It is hard to accept that these are over. Science has lost a creative thinker: we have lost a great colleague and a good friend.

Adrian Baddeley (Perth)

One balmy evening in Spain, a bus waited to pick up the guests from a conference dinner to take them back to their hotels. A young man, with a troubled look about him, sat at the back of the bus, gazing vacantly at the city, and contemplating the mess that was his personal life. His eyes came to rest on a spray of bullet holes from the Civil War, still clearly visible on the facade of the historic restaurant.

Suddenly a figure loomed - bustling, animated, courteous - and took the next seat, introducing himself as Julian Besag. Perhaps it was the instinctive recognition of another troubled soul; perhaps there was some alcohol involved; but within a few minutes, Julian Besag had confessed to me like an old friend that his scientific career was a failure. Yes, Julian's early flashes of talent and promise, and the high regard in which he was held by Maurice Bartlett, had ended in disappointment and burnout. The brilliant career of J.E. Besag was over by 1983. Gloom descended. I gazed back at the bullet holes.

But there was one thing, Julian said, almost as an afterthought, his voice brightening: there was one new curiosity that was keeping him entertained. Something to do with digital images. I expressed an interest, and Julian began to explain, succinctly, clearly and with increasing animation: lattice data; agricultural field trials; Markov random fields; conditioning; pseudolikelihood; digital images; Don and Stu Geman; Bayesian inference; conditional modes. And where it all might lead: spatial statistics; conditional simulation; a rich vein of elegant scientific ideas, and a far-reaching research programme, stretched out before us like a promised land. It was wonderful, exhilarating. "Well, here's my hotel", said Julian abruptly, shaking hands and bolting for the door, gone as quickly as he had come. I sat, stunned, as the bus drove off. Thus ended the most important ten minutes of my life.

Don Geman (Johns Hopkins)

Among many other anecdotes I could recall, Julian was at the source of the most amazing coincidence of my life. One winter evening many years ago in Cambridge (UK) I was trying to find the location on a city map of the house where I was going to dinner. I could barely read the map. A kind stranger came to help me and we moved together under a street light. We were both looking at the map. After some time, I said "Julian?" and he said "Don?". Incredibly, as well as we knew each other, neither of us immediately recognized the other. And neither knew the other was in Cambridge.

Anyway, there are other stories I could tell, some more controversial, and some attesting to his astonishing intuition (Peter Green was there for one of them in 1986 involving an experiment Gidas had done that Julian said must have a bug). Without a doubt, Julian was one of the most remarkable people I have ever encountered and I dearly miss having him in our world.

Brce Porteous (Edinburgh)

I was a member of the Durham University Statistics Department between 1985 and 1988 and had the very great privilege of working with Julian, Peter and Allan over this relatively short period.

When I went up to Durham from Cambridge for my interview, Julian already had a very well established reputation as a fearsome character who did not suffer fools lightly - I travelled fully expecting my inadequacies to be thoroughly exposed. I think that what helped me through was some practical knowledge of a spatial data set that Julian knew well.

I found Julian (and Peter and Allan) to be straightforward, hugely committed to their subject, fun to be with and, despite reputations that were already reaching the heights, completely lacking in pretension. A Julian inspired approach based on genuine scientific insight, and not just highly technical mathematics, was hugely refreshing and I soon realised that I was a novice in their company.

Looking back, I have a very large number of fond memories of Julian that, for some reason, still remain fresh in the mind - probably due to his unique and somewhat unconventional character and style. Two examples, from many, are:

1. I was running a simulated annealing experiment one evening when Julian came in, sat down and started chatting. As he watched the image pixels change, he began to stare intently at the computer screen. After a few minutes he informed me that there was a mistake in the programme and what it was. On inspection we found that he was right and had somehow identified a very subtle coding error.
2. Having read the other contributions, I now realise that the RSS train ride to London with Julian was, should we say, often colourful. On one trip back to Durham I got caught up in a "discussion" between Julian and the ticket collector and which also involved a large number of other passengers including Peter Green. The Besag view prevailed.

The last time I saw Julian was at Allan's retirement a few years ago. I entered the lecture theatre unseen as Julian was preparing his presentation - when he saw me he rushed over, using a crab-like gait due to his mobility constraints, to say hello and shake my hand - it felt really good to be welcomed like that after 20 years.

Although I knew Julian for a short period of time many years ago, he is someone I have not, and certainly will not, forget. I feel immensely proud to have known and learned from him.

Stephen Duffy (London)

I worked in Julian Besag's group in Durham in 1986. When I first met him, I was struck by his rather grumpy manner. However, I always got on well with him, partly because of a common interest in drinking too much pop. Also, he was very encouraging, indeed flattering, about my applied and data analytic work, despite its being theoretically trivial in comparison with the sort of research Julian did. Along with the bear with a sore head persona went a great generosity of spirit.

Kerrie Mengersen (Brisbane)

Here at the other end of the world, I am reading a draft of a paper by a student on spatio-temporal analysis of data from an agricultural experiment on greenhouse gas emissions, and I have at my side a brand new copy of the first Queensland Cancer Atlas produced by another student. Both of these are based on models and methods developed by Julian and they are testimony to the living legacy of his contributions to Bayesian statistics. But they are more than this: just as Julian invested time to teach me about Bayesian modelling and MCMC in my early career, so his work continues to boost the careers of these young people. Julian taught me the principles of MCMC in the sand on the beach at the Gold Coast in Australia. He then taught me the principles of Bayesian modelling and allowed me to participate in a paper on the topic that acted as a surfboard for the wildest ride in applied Bayesian statistics over the last two decades. He taught me rigour in writing, ways of seeing problems and models, confidence in asking basic questions, and a desire to answer them. He is missed.

John Matthews (Newcastle upon Tyne)

I am sorry that I cannot attend Julian's memorial meeting but the email to those unable to attend mentioned the possibility of written contributions. This has given me the opportunity to set down some reminiscences about one of Julian's lesser known appointments. For several years from the late 1980s, Julian was Visiting Professor of Medical Statistics in the Medical School at the University of Newcastle. He held this appointment towards the end of his tenure of his Chair at Durham and it arose because of a high-profile issue in spatial epidemiology.

Around that time there had been speculation about the possible role of emissions from the Sellafield nuclear facility in the aetiology of several "clusters" of cases of childhood leukaemia in West Cumbria. The matter had received national attention through a television programme (Windscale - the Nuclear Laundry, Yorkshire TV) and some confirmation of the role of the facility was claimed following an analysis by a Newcastle geographer, Stan Openshaw. The analysis was a genuine attempt to address the problem, and was not without merit but, to a statistician's eye, it certainly lacked a great deal in professionalism and, possibly, a good deal in validity. Julian put this succinctly when he attended a meeting of the North East local group of the RSS and asked me "What the hell is Stan playing at?" It was only later that I learnt that Julian had for a long time had a love-hate relationship with geographers, and not one that was equally weighted on these two components.

David Appleton, then Head of Medical Statistics in Newcastle, managed to arrange a collaboration to re-visit the analysis of the Sellafield data, the principal players being Julian, Stan and Alan (now Sir Alan) Craft, the paediatrician who had collected the data now being scrutinised. In due course a research grant was obtained to employ an RA, James Newell, and then the matter of where James should be located arose. Should he be in Durham, where Julian was, or in Newcastle, where the data were? Although Julian worked in Durham, where his University was, he lived in Newcastle, where his hockey was. The delicate negotiations over the location of the RA were finally concluded when David pointed out that Visiting Professors at Newcastle were entitled to a car parking permit. For those of you who do not know the place, the University of Newcastle is conveniently located in the centre of the city.

The research project now proceeded to a successful conclusion, both in terms of the relationship between Julian and Stan, which developed into amity and a considerable degree of mutual respect, and in terms of the work, which resulted in a paper by Julian and James (JRSS(A), 1991, 154, 143-155), which has been cited 442 times (Mar 2011, Google Scholar).

It was almost always a pleasure to have Julian around the Department and, as he lived in Newcastle, we saw him quite frequently. You need to remember that this reminiscence harks back to the days of mainframe computing and, in the Universities of the North East of England, this meant NUMAC, a consortium that allowed academics at Durham and Newcastle to log on to their mainframe from either institution. The attractions of the Department were further enhanced because David Appleton always ensured lavish, indeed some would say inconveniently excessive, provision of APL keyboards. So attractive was the Department that Julian often came in to work on things other than the Sellafield project. A good deal of his collaboration with Annie Mollié (Besag, York and Mollié, Ann Inst Math Statist, 1991, 43, 1-20, cited 1145 times) happened in the Department and through this we got to know Annie quite well.

Indeed, when it came time for Annie to return to France we all went out to a local Indian restaurant. I say "local" but it was a mile or two from the Medical School. About half way through the meal someone said "Any idea where Julian has gone?" Looking around, a lonely chicken bhuna could be seen unattended at the end of the table. Then Annie said that she thought Julian might have gone to check the computer, as he had set some simulations running before coming to the restaurant. There was a degree of dismay that someone could have gone over a mile to look at his simulations in the middle of dinner, but we soon came to our senses, as we realised this was Julian and we all laughed in admiration of this mildly eccentric dedication to his research. All of us except David, who had gone rather quiet. He then said "Do you really think he has gone to look at the computer? It's a pity if he has because I turned off all the terminals before leaving the Department". About thirty minutes later Julian jogged back in to the restaurant, looking a little hot and bothered, and said that he had been to check his simulations but had been disappointed to find that the terminal had been switched off. These may not have been his exact words.

Shirley Coleman (Newcastle upon Tyne)

Julian was great fun. I first got to know him at the Guy Fawkes night bonfire and fireworks party at Close House, then owned by Newcastle University, in the Tyne Valley. My friend and I bundled Julian and two other Durham Professors into the back of my Moskvich estate car and gave them a lift back to Newcastle. Later Julian came to my wedding party bringing two bottles of red wine and ending up sleeping the night on a chaise longue in front of the open fire. We met at the Spatial Statistics RSS conference in Scotland where, as always, he was very gracious with all the contributors and very modest whilst presenting his own brilliant work. I last saw Julian at Bath University and, although clearly unwell, he was his same warm self. He was a great person and I am very sorry not to have him around.

Peter Green, School of Mathematics, University of Bristol, Bristol, BS8 1TW, UK.
Email link Telephone: +44 (0)117 928 7967; Fax: +44 (0)117 928 7999