Marlborough, John Churchill, 1st duke of (1650–1722). The most successful general of his age, Marlborough was from 1704 until 1710 the leading European statesman, eclipsing even Louis XIV. Son of an impoverished royalist squire he owed the start of his dual career as courtier and soldier to the future James II. He gained military experience in Tangier and under Turenne in the French service. From page he became confidential emissary to James, and in 1685 after playing a decisive part in defeating Monmouth's rebel army he became a major-general. After 1683 he and his wife Sarah also developed an intimate and lasting connection with the future queen Anne.

Churchill made a massive contribution to the success of the Glorious Revolution by organizing a network of officers who defected to William, so preventing James from making William fight a Bosworth-style battle. As reward he became earl of Marlborough. He organized and led a combined operation that took Cork and Kinsale in southern Ireland (1690), but by championing Anne against her sister Mary he provoked his dismissal from all posts (1692). Alienated, he made promises to Jacobite agents but this was principally an insurance policy against James's possible restoration.

After 1700, faced with an impending European war and broken in health, William designated Marlborough to command the British forces in the Low Countries, disregarding both his past behaviour and his inexperience as a general. William's purpose was to ensure the continuation of his policy of containing and reducing French power, and the Dutch alliance, when Anne succeeded. In 1702 Marlborough, commanding Dutch forces also, manœuvred the French out of territories bordering on the Dutch Republic. Anne made him duke. In 1703 the Dutch generals obstructed his offensive plans, fearing to risk everything on a major battle. But in 1704 French armies in Bavaria threatened to force the German allied princes to capitulate, isolating Britain's other major ally, the Emperor. However, these French armies put themselves in a strategically and logistically untenable position. Superb organization enabled Marlborough to march his army to the Danube where at Blenheim (13 August) he inflicted the greatest defeat the French had suffered for 150 years. Blenheim was fought in partnership with Eugene, the Emperor's general, with whom Marlborough worked harmoniously. Skill as a diplomat was vitally important since success depended on Marlborough holding the alliance together, a task that became more difficult as French defeats made the allies less fearful of Louis XIV. Marlborough pioneered personal diplomacy, travelling to Vienna, Berlin, and Hanover, and corresponding continually with allied sovereigns and ministers. In 1707 he diverted Charles XII of Sweden from attacking the emperor, and so disrupting the alliance.

In 1705 Marlborough failed in an invasion of France up the Moselle valley, but in 1706 he won a second massive victory at Ramillies and overran most of the Spanish Netherlands. This achievement was soured when the Dutch reaction made him decline the Emperor's offer of the lucrative governor-generalship of these provinces. In 1708 he totally defeated a French counter-offensive at Oudenarde, took the fortress of Lille, and planned a final invasion of France. The excessively expensive victory of Malplaquet (September 1709) prevented this and convinced a war-weary Britain that Marlborough and the Godolphin ministry were committed to an endless war. Swift pilloried him as motivated purely by greed. Dismissed by the Tory government in December 1711 Marlborough exiled himself. Reinstated by George I as captain-general, he supervised suppression of the Jacobite rebellion in 1715.

J. R. Jones

Marlborough, John Churchill, 1st Duke of (1650–1722) English general. Churchill helped James II defeat Monmouth (1685), but switched allegiance in support of the Protestant Glorious Revolution (1688). Partly due to his wife's friendship with Queen Anne, he was appointed Captain-General of Allied armies in the War of the Spanish Succession. His strategic skill gained great victories at Blenheim (1704), Ramillies (1706), Oudenaarde (1708), and Malplaquet (1709). Churchill was rewarded with a dukedom and Blenheim Palace. When his wife lost the Queen's favour and the Tories regained power, Malborough was dismissed (1711) and went into exile.