Professor Dominic Welsh 1938 – 2023

With great sadness, we announce the loss of Professor James Anthony Dominic Welsh.

Dominic was a student at Merton and later became a Fellow in 1966. He taught and inspired a great number of students as a Professor of Mathematics. Dominic was Chairman of Mathematics at Oxford for a five-year term, the culmination of a sequence of significant administrative posts.

Dominic was a leading contributor to combinatorial mathematics and received an honorary doctorate from the University of Waterloo in 2006.

In 2007, Oxford University press published Combinatorics, Complexity, and Chance: A Tribute to Dominic Welsh, an edited volume of research papers. The Abstract reads ‘Professor Dominic Welsh … made significant contributions to the fields of combinatorics and discrete probability, including matroids, complexity, and percolation. He … taught, influenced, and inspired generations of students and researchers in mathematics.’

The Russo–Seymour–Welsh estimate in percolation theory is partly named after Dominic due to the influence of his Doctoral Thesis; ‘On stochastic processes, with special reference to percolation theory’.

'Dominic was a much loved tutor who inspired his students to do their best. His love for mathematics and problems solving was infectious. But beyond that he believed in the individual and valued effort more than ability.  Many of his students went on to have flourishing careers in academia and beyond. I was fortunate to work along side with Dominic for thirteen years as mathematics tutor and learnt a lot from him.

He was a much valued colleague and loyal to the College of which he was a member for most of his live: first as a student, then as tutor and fellow. While Principal of Postmasters his compassionate approach shone through and he and his wife Bridget offered many a student a home away from home. He was a much valued colleague at Merton and at the Mathematical Institute which he led as departmental chairman for several years in the 1990s.

His legacy will live on through his students, both undergraduate and graduate, his many books on probability, matroids, codes and cryptography, and his research published in more than 100 papers. He will be much missed.'

-Professor Ulrike Tillman

Our sincerest condolences to Dominic’s family and friends.