This morning brought the news that Jan Saxl died on Saturday.
Jan arrived in Britain in the early autumn of 1968, as did I: a very significant time for Czechoslovakia. (I spent six weeks in Earls Court, in London, before term started in Oxford; the first I knew about events was when I went to see a Soviet exhibition in Holland Park and found the exhibition hall surrounded by demonstrators.)
He is my mathematical brother, a student of Peter Neumann, taking his DPhil just two years after I did. (I have a vague memory that I was nominally his supervisor for a very short time while Peter Neumann was away, but I may be confusing him with David Cooper.) We collaborated on four papers; the best-known is the proof of the Sims conjecture, joint also with Cheryl Praeger and Gary Seitz.
Of course he had many collaborations with other mathematicians, especially Martin Liebeck and Cheryl Praeger, and produced some work of very great significance to the finite group theory community and more widely.
Jan was a good friend. When I directed a six-month programme on Combinatorics and Statistical Mechanics at the Isaac Newton Institute in 2008, he arranged for me to have a visiting fellowship, with a flat in Rose Crescent (up the stairs above the famous Gardenia) and lunches and dinners with the College fellows; the small price I had to pay was to give “three or four lectures” to the maths students in the College, which of course I was delighted to do.
Jan is someone who touched many people deeply. The world seems a greyer place without him. I hardly know what to say.