The son of Sir Thomas Egerton and Elizabeth Ravenscroft, he matriculated at Brasenose College, Oxford in 1589 at the age of 10, graduating as Bachelor of Arts in 1594.

In 1603, Sir Thomas was promoted Knight of the Bath and, in 1605, he proceeded Master of Arts from the University of Oxford.

John Milton's Comus celebrates his installation as Lord President of Wales.

The Egertons later built a domestic chapel with burial vault at Little Gaddesden Church,[3] where many monuments commemorate the Dukes and Earls of Bridgewater and their relatives.

On 27 June 1602,[5] Egerton married Lady Frances Stanley, daughter of Ferdinando, 5th Earl of Derby and Lady Alice Spencer, Lord Bridgewater's step-mother (after Ferdinando Stanley's death, on 20 October 1600,[6] Lady Alice had married John's father Thomas Egerton, 1st Viscount Brackley).