[1] He was born at Denham, Buckinghamshire, the third but only surviving son of William Cooke (1711–1797), provost of King's College, Cambridge and his wife, Catherine, the daughter of Richard Sleech, a canon of St George's Chapel, Windsor.
He had an extremely poor opinion of the Irish judiciary, and sent jaundiced letters to London describing nearly all of them as insolent, ignorant or biased.
The Lord Lieutenant consented to his retirement, and he received sinecure posts worth £2000 per year, including Keeper of the records of the Irish parliament.
Following his return to England, Cooke remained unemployed until 1804, when he was appointed Under-Secretary of State for War and the Colonies under Lord Camden and then Viscount Castlereagh.
Cooke married, on 10 August 1791, Isabella, the daughter of Hamilton Gorges of Kilbrew, Co. Meath, an Irish MP.