Egerton was born in Indore, India, on 21 July 1932.
Egerton returned to England aged 11 to be educated at Eton College, where he won the Newcastle Scholarship.
After National Service in the King's Royal Rifle Corps, he read classics at Trinity College, Cambridge.
He joined the Foreign Service in 1956, and had a succession of posts including Kuwait, Iraq, New York and Tripoli.
He served as British ambassador to Iraq from 1980 to 1982, and to Saudi Arabia from 1986 to 1989.