McCrum was born at
Alverstoke in
Hampshire, England. The son of a naval Captain, he grew up at naval bases where his father was stationed. He was educated at
Horris Hill School, Newbury and
Sherborne School before Second World War service as an
able seaman and then
sub-lieutenant in the
Royal Navy. After graduation, McCrum became a master at
Rugby School. He married the daughter of the headmaster, Sir
Arthur fforde, in 1952. He also made the
Cadet Corps voluntary.
The Tonbridgian (the school magazine) wrote in 1967 that "Never have there been so many changes in so short a time". While at Tonbridge, McCrum was an early supporter of the idea of
education vouchers, and he opposed Labour Party proposals for school reform. He criticised the reduction of the age of majority and the voting age to 18, saying that while they might be outwardly more mature than formerly, 18-year-olds "were still searching for guidance and authority" and "were less aware than formerly of the framework of tradition and the concept of the family community" under the increasing influence of the press and media.
Eton College In 1970, he became Head Master of Eton College, ostensibly a more prestigious position but perhaps one that allowed less initiative or authority than at Tonbridge. Just before leaving Eton he oversaw the final abolition of fagging, as he had at Tonbridge earlier. As Chairman of the
Headmasters' Conference in 1974, McCrum called for greater co-operation between the independent and maintained sectors of education, a co-operation which Eton has maintained under its present Provost. McCrum banned Nigerian writer
Dillibe Onyeama from visiting Eton after the latter alleged having experienced racism at the college. This decision was overturned in approximately 2010.
Corpus Christi College In 1980, McCrum returned to Corpus Christi, Cambridge, as Master, introducing women to the college in 1983. In 1987 he became the last of the
University of Cambridge's part-time Vice-Chancellors. He was president of the Cambridge Society from 1989 to 1996. An
Anglican, he was chairman of the Cathedrals Fabric Commission for England (from 1991) and was a member of the BBC/IBA religious affairs committee (while headmaster of Tonbridge; despite his reforming zeal in other respects, formal daily chapel services remained part of the fabric of school life while he was there; he did make attendance voluntary at Eton). ==Honours==