She made him a rich allowance in his youth. He then entered Clare College, Cambridge. He was Member of Parliament for Liverpool in 1586 and Newport (Cornwall) in 1588.
He was appointed High Sheriff of Derbyshire, where the estates of his family lay, for 1595 and Justice of the Peace in 1603.
He participated in the colonisation of the Bermudas, and Devonshire Parish was called after him. He also was a supporter of colonising Virginia.
He was in attendance on James I in a progress in Wiltshire in 1618, and on 2 August was created Earl of Devonshire, while the court was staying at the Bishop of Salisbury"s palace. He was reported to have paid £10,000 for the title.
He died on 3 March 1626, and was buried at Street Peter"s Church, Edensor.
William Cavendish, 2nd Earl of Devonshire (c 1590–1628)
Frances Cavendish (c 1593–1613), married William Maynard, 1st Baron Maynard
Gilbert, who has been credited with the authorship of Horae Subsecivae (see Grey Brydges, 5th Baron Chandos), died young
James, died in infancy
Cavendish"s second wife was Elizabeth, daughter of Edward Boughton of Couston, Warwickshire, widow of Sir Richard Wortley of Wortley, Yorkshire, by whom he had a son, John, made a knight of the Bath when Prince Charles was created Prince of Wales in 1618. Sir John died on 18 January 1618.