[1] Walker was educated at Leeds Grammar School and The Queen's College, Oxford.
[2][3] During the Second World War, he served in the Royal Naval Volunteer Reserve (RNVR).
His first ordained ministry position was a curacy at Hemel Hempstead, after which he was fellow, dean and lecturer at Corpus Christi College, Cambridge.
[5] In 1972 he was consecrated to the episcopate as the Suffragan Bishop of Dorchester.
[6] In 1977 he was translated to become the Bishop of Ely, a position he held until his retirement in 1989.