Marriage to Sarah Jennings and her relationship with Anne ensured Marlborough's rise, first to the captain-generalcy of British forces, then to a dukedom. As de facto leader of Allied forces in the Low Countries, his victories at Blenheim (1704), Ramillies (1706), Oudenarde (1708), and Malplaquet (1709) ensured his place in history as one of Europe's great generals.