Consuelo Vanderbilt Balsan was an American socialite. She was a member of the Vanderbilt family and only daughter of William Kissam Vanderbilt and Alva Erskine Smith. Her first marriage to Charles Spencer-Churchill, 9th Duke of Marlborough has become a well-known example of the advantageous but loveless marriages common during the Gilded Age. The Duke obtained a large dowry through the marriage and reportedly told her — on their honeymoon — that he had married her only "because he felt obliged to save Blenheim," his ancestral home.