Newcastle, Thomas Pelham-Holles, 1st Duke of

Newcastle, Thomas Pelham-Holles, 1st Duke of (1693-1768), British statesman, Prime Minister of Great Britain (1754-1756; 1757-1762). Born in London, he was educated at Winchester and Clare College, Cambridge University. As a Pelham, he inherited the estates of his uncle, John Holles, Duke of Newcastle, and adopted his name and the title of the Earl of Clare, which gave him a seat in the House of Lords that he took up in 1714. A firm Whig and supporter of the House of Hanover, he used his considerable wealth and influence in securing the succession of George I, who rewarded him by conferring upon him the dukedom of Newcastle. By his marriage to the daughter of the Duke of Marlborough, Newcastle secured himself in the Whig oligarchy and he served as Secretary of State for 30 years from 1724 under Robert Walpole, Spencer Compton, and his brother, Henry Pelham.

He succeeded his brother as prime minister, on the latter’s death in 1754, just as Anglo-French relations in North America were deteriorating into the French and Indian War. Newcastle was blamed for British reverses in the opening phase of the ensuing Seven Years' War, and resigned from office in favour of William Cavendish, but was returned to office after seven months in a coalition ministry with William Pitt as Secretary of State. While Pitt directed the conclusion of the war, Newcastle served as a party man and manager of Parliament.

The accession of George III in 1760, who supported the promotion of his former tutor the Earl of Bute, saw an attempt on the part of the king to blunt Newcastle’s political influence. As his supporters were dismissed from office, so Newcastle was forced to resign in 1762, to be replaced by Bute. He became increasingly politically isolated, although in 1765 served briefly as Lord Privy Seal in the ministry of his protégé, the Marquess of Rockingham.