The Society of Antiquaries has published a brief obituary for Dr Jim Summerly, which can be accessed here. Dr Summerly completed his PhD at Durham University under the supervision of Brian Dobson. He was one of an influential group of historians and archaeologists who studied aspects of the Roman army at Durham University, a trend begun by the masterly teaching of Eric Birley. Dr Summerly became an authority on Hadrian's Wall and acted as a guide for recent pilgrimages to Hadrian's Wall.
I never had the pleasure to meet Dr Summerly. However, I am very familiar with his work as I read his PhD thesis entitled 'Studies in the Legionary Centurionate' during the course of my own research. I have happy memories of spending a few days pouring over the manuscript in Durham University library. The thesis was a fascinating piece of work which highlighted a number of interesting patterns in the recruitment and career patterns of legionary centurions. As far as I am aware, the thesis was never published. This is a shame, as I am sure that it would be guaranteed a wide readership among Roman military scholars and enthusiasts alike.