John Holmes had moved from London to Wales to marry Margaret, whom he met on a cycling holiday.
[1] Holmes was educated at Ardwyn County School and University College, Aberystwyth.
After having a year abroad at the University of Göttingen, in 1952-53, he moved to Oxford in 1954, where he became Tutor in Modern History at St Catherine's Society.
When the University granted that Society full collegiate status, he became one of the founding Fellows of St Catherine's College, Oxford at its foundation in 1962.
Elected a Fellow of the British Academy in 1985, he also served for many years as Delegate to Oxford University Press.