The Duchess of Marlborough refers to several women who held the title, most notably Sarah Churchill, the first Duchess, who was a prominent figure in the early 18th century. She was a close friend and confidante of Queen Anne and played a significant role in political affairs during her reign. Sarah was known for her influence and her involvement in the War of the Spanish Succession. The title of Duchess of Marlborough was created in 1702 and is associated with the Marlborough family, which has a rich history in British nobility. The family estate, Blenheim Palace, is a UNESCO World Heritage site and was built to honor the Duke's military victories.