He was educated at Eton College, Windsor, Berkshire, England and was educated at Royal Military College, Sandhurst, Berkshire, England.
Egerton fought in the First World War, and was mentioned in despatches. He gained the rank of Captain in the service of the 1st Battalion, Grenadier Guards.
He married Helen Bendelari (daughter of Fred Bendelari) on 19 September 1927 at St George, Hanover Square, Middlesex, England.
They were divorced in 1934.
He married, secondly, Noeline Cyprienne Catherine Ancram Hare Waller-Bridge (daughter of Reverend Horace FitzHenry Waller-Bridge and Elsie Noëline Waller Ward-Boughton-Leigh) on 19 December 1952 at Marylebone, London, England.
"England and Wales Census, 1901," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:XS8M-Z2Z : 29 August 2015), Egerton Leigh in household of John Hugh Ward Boughton Leigh, Rugby, Warwickshire, England; from "1901 England, Scotland and Wales census,"