Dunk, George Montagu (1716–71), 2nd earl of Halifax , lord lieutenant of Ireland, was born 5/6 October 1716, the son of George Montagu (d. 1739), 1st earl of Halifax, whose seat was at Horton, Northamptonshire, and his wife, Lady Mary Lumley (1690–1726), daughter of the 1st earl of Scarborough. Known, until he succeeded to the earldom (9 May 1739), as Viscount Sunbury, he was educated at Eton College and Trinity College, Cambridge. On marrying (2 July 1741) Ann Dunk, he added both her fortune (over £100,000) and her surname to his own. During the Jacobite invasion (1745) he volunteered to raise a regiment; he was made a colonel and, though the proposed regiment did not materialise and he was never on active service, he was promoted to major general (1755) and lieutenant general (1759). Halifax was president of the Board of Trade from 1748.
His first connection with Ireland was made shortly after the death of his wife (13 October 1753), when he engaged as governess to his three daughters an Irishwoman, a singer at the Drury Lane theatre, Mary Anne Donaldson, niece and adopted daughter of George Faulkner (qv), who had been deserted by her husband. She soon became Dunk's mistress and bore him a son and a daughter. The second was his appointment as lord lieutenant of Ireland on 20 March 1761. His arrival in Ireland was delayed by the coronation of George III, but he eventually made the journey in the early autumn, accompanied by his chief secretary, William Gerard Hamilton (qv), his second secretary, the dramatist Richard Cumberland, and his mistress, Mrs Donaldson; he disembarked on 6 October and was sworn in. His policy was eirenic. By careful diplomacy he got the Irish house of commons to pass an unpopular money bill (20 November). The heads of a septennial bill (to limit Irish parliaments to seven years), which he disliked, he allowed to pass (February 1762) in order that it might be rejected by the English privy council. While pressing magistrates to act against the agrarian protests of the Whiteboys, who first disrupted the peace of the Munster countryside in the early months of 1762, he discounted assertions that they had sectarian or political motives.
After England declared war on Spain (January 1762), Halifax took stock of Ireland's defences. Anxious to return to a political career in London, he left Ireland on 1 May 1762, confiding affairs to lords justices and formally continuing in office until 27 April 1763, when his successor, the first duke of Northumberland (qv), was appointed. He served as first lord of the admiralty (1762), secretary of state (1762; 1771), and lord privy seal (1770). Halifax died 8 June 1771 at Horton.