Sarah Churchill (1660-1744), Duchess of Marlborough, was born Sarah Jennings and rose to be one of the most influential women in the whole of British history, largely as a result of her close friendship with Queen Anne. This came about some time after 1673, when she joined the household of the Duke of York (later to be King James II of England) and befriended his younger daughter; Anne was a few years Sarah's junior. They called one another by pet names, Sarah being "Mrs. Freeman" and Anne "Mrs. Morley". In 1677, Sarah married John Churchill, later to be created Duke of Marlborough, and they made a glittering couple. Churchill, though he had supported James, also had a role in bringing William of Orange to the British throne and was rewarded with an earldom.
Following Anne's accession to the throne, Sarah was made Mistress of the Robes and Keeper of the Privy Purse. She exercised great personal and political influence. However, the introduction into Anne's household of a politically aware rival, Sarah's own cousin, Abigail Hill (later Mrs. Masham), the relationship between the queen and her old friend deteriorated greatly. In 1711, both Sarah and her husband fell out of royal favor. Anne's death in 1714 restored their fortunes, but the Duke died in 1722 and never saw the completion of Blenheim Palace, the house built for him by a grateful nation. It was left to Sarah to oversee the remaining work, and she was often in conflict with the architect, Sir John Vanbrugh. Close links with the royal family remained; Sarah sought to marry one of her granddaughters to Frederick, Prince of Wales, and remained friendly with the prince and his family even after this plan had failed.