Elected Whig MP for Buckingham in 1741 (a seat he represented throughout his political career until he left the House of Commons in 1770), Grenville was an early supporter, along with his brother-in-law William Pitt the Elder, of the “Boy Patriot” group lead by Lord Cobham which opposed the then Prime Minister Sir Robert Walpole. He joined the administration of Henry Pelham as a Lord of the Admiralty and served in a succession of Whig governments in the 1740s and 50s. Later estranged from Pitt, Grenville served Tory Lord Bute, eventually succeeding him as Prime Minister. During his term in office, Grenville prosecuted John Wilkes for seditious libel and introduced the Sugar and Stamp Acts which caused great resentment in the American Colonies. Never on good terms with George III, Grenville fell out with the King over who should rule in the event of the King’s becoming mentally unfit which led to Grenville’s dismissal never to return to high office.