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 Street George"s Chapel, Windsor.
He was educated at Eton and King"s College, Cambridge, graduating with a Bachelor in 1777 and Master of Arts in 1785, being a fellow of the college from 1776 to 1786.
Cooke entered government service in 1778, as private secretary to Sir Richard Heron, the Chief Secretary for while John Hobart, 2nd Earl of Buckinghamshire was Lord Lieutenant of He served in a series of posts in the Irish administration and parliament, becoming under-secretary for the military department in 1789-1796 and for the civil department 1796-1801. He prospered because he was clever and ready to support British policy. 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.
He published several political pamphlets during the 1790s.
However, his position became difficult during the passage of the Irish Acting of Union, because he favoured relief to Catholics. This determined him to return to England.
While in London in 1801, negotiating the augmentation of the Irish Secret Service Fund, he was in negotiation with Lord Pelham over his future employment and Pelham"s under-secretary, but a row broke out over the respective role of the Home Secretary and the Lord Lieutenant. 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. His career then followed Castlereagh"s to the Foreign Office. He went with him to Vienna and to Italy in winter 1814-1815 to support Castlereagh in peace negotiations and partly to negotiate with the Vatican over the Catholic Question.
In 1817, he retired, much to his chief"s regret.
Cooke married, on 10 August 1791, Isabella, the daughter of Hamilton Gorges of Kilbrew, Company Meath, an Irish Member of Parliament. There were no children.
He died in 1820.
In this period, he was also Member of Parliament (Member of Parliament) for the boroughs of Lifford (1789-1790) and Old Leighlin (1789–1801).
