The Duke of Marlborough holds certain subsidiary titles: Marquess of Blandford (created 1702), Earl of Sunderland (1643), Earl of Marlborough (1689), Baron Spencer of Wormleighton (1603) and Lord Churchill (1685). (The Lordship of Churchill is in the Scottish peerage, while the rest are in the English peerage.) The title Marquess of Blandford is used as the courtesy title for the Duke's eldest son and heir.
The later Dukes of Marlborough are descended from the first duke, but not in the male line. Because the first duke had no sons, the title was allowed (by a special Act of Parliament) to pass to his eldest daughter in her own right. A younger daughter, Lady Anne Churchill, married Charles Spencer, 3rd Earl of Sunderland (c. 1674 - 1722), and from this marriage descend the modern Dukes of Marlborough. They therefore originally bore the surname Spencer. However, George Spencer, the 5th Duke of Marlborough, obtained a Royal Licence to assume and bear the additional surname and arms of his famous ancestor, the 1st Duke of Marlborough, and thus became George Spencer-Churchill. This double-barrelled surname has remained in the family to this day.
The 7th Duke of Marlborough was the paternal grandfather of the British Prime Minister Sir Winston Churchill.
The present Duke of Marlborough is John George Vanderbilt Spencer-Churchill, 11th Duke of Marlborough.
Dukes of Marlborough
See also: Spencer family