Born in
Bromley, he was educated at
City of London School A fellow of
Peterhouse, Cambridge, from 1963 to 2003, in 1967 he invented a geometric shape called Croft's Tortoise and in 1991 he co-authored
Unsolved Problems in Geometry with
Kenneth Falconer and
Richard K. Guy. Croft clashed with
Hugh Trevor-Roper after the latter became Master of Peterhouse in 1980 when Croft was Director of Studies in mathematics and Senior Fellow; Croft's conservatism led him to deeply dislike Trevor-Roper, and the upshot was that he was re-elected as a Fellow in 1983 without his seniority. Friends suggested that Trevor-Roper disliked Croft because of his homosexuality. ==References==