Consuelo Vanderbilt Balsan (formerly Consuelo Spencer-Churchill, Duchess of Marlborough; born Consuelo Vanderbilt; 2 March 1877 – 6 December 1964) was a member of the prominent American Vanderbilt family. Her first marriage to the ninth Duke of Marlborough has become a well-known example of one of the advantageous, but loveless, marriages common during the Gilded Age. The Duke obtained a large dowry by the marriage. Although the teenage Consuelo was opposed to the marriage arranged by her mother, she became a popular and influential Duchess. For much of the marriage, they lived separately and the marriage was finally annulled. She went on to marry a wealthy French aviator and continued her charitable endeavours. Her marriage produced two sons John Spencer-Churchill and Lord Ivor Spencer-Ch