John Churchill Marlborough, 1st duke of (märl´bərə, môl´–), 1650–1722, English general and statesman, one of the greatest military commanders of history. A great strategist and a shrewd diplomat, he has been criticized for inordinate love of wealth and power and for inconstant loyalties in politics.
Under James II and William III
The son of an impoverished squire, he became (1665) a page of the duke of York (later James II) and entered (1667) the army. He rose rapidly under York's patronage and c.1678 married Sarah Jennings (see Marlborough, Sarah Churchill, duchess of), attendant and friend of Princess (later Queen) Anne. Under James II he was active in crushing the rebellion (1685) of the duke of Monmouth and was raised to the peerage and made a major general.
Nevertheless, fearing the religious policies of the Roman Catholic king, and concerned about his own career, he corresponded with William of Orange (later William III) and supported him against James in the Glorious Revolution of 1688. He was created earl of Marlborough at William's coronation (1689). Marlborough was successful as a military commander in 1689 and 1690, but William's poor treatment of Anne offended him, and William began to resent Marlborough's ambition and ability. When Marlborough began secret communication with the exiled James II, he was discovered and lost royal favor (1692–98).
Power and Dismissal under Anne
In 1702, when Anne ascended the throne, Marlborough reached the fullness of his power. His military genius and remarkable gift for foreign diplomacy were given wide scope in the War of the Spanish Succession. His personal efforts long held together the anti-French alliance. He and Prince Eugene of Savoy together won such victories as Blenheim (1704), Oudenarde (1708), and Malplaquet (1709), and he alone is credited with Ramillies (1706) and countless other triumphs.
Marlborough, made a duke in 1702, also enjoyed political ascendancy, largely as a result of his wife's influence over the queen. Marlborough and his friend Sidney Godolphin, as well as the queen, although earlier bound by personal and religious ties to the Tories, turned to the Whigs, who favored the war while the Tories opposed it. They secured the dismissal of Robert Harley in 1708 and were momentarily paramount in politics. The duchess, however, quarreled with Anne, who came under the influence of Abigail Masham, Harley's cousin; the war was costly, and Marlborough was accused of prolonging it for his personal glory; the prosecution of Henry Sacheverell was unpopular; and in 1710 the Whigs fell, yielding power to Harley and Henry St. John (later Viscount Bolingbroke).
The duke was falsely charged with misappropriating public funds and was dismissed (1711) from office. He returned to England from self-imposed exile upon the accession of George I in 1714 and was given chief command of the army again, but he took little further part in public affairs.
See the duke's letters and dispatches (ed. by Sir George Murray, 1845); the exhaustive biography of him by his descendant Winston S. Churchill (1933–38, repr. 1982) and a short one by M. P. Ashley (1939, repr. 1957); studies by C. T. Atkinson (1921), F. Taylor (1921), I. F. Burton (1968), D. G. Chandler (1973), and D. W. Jones (1988).