This is a dual biography, exploring the lives of John and Sarah Churchill, first Duke and Duchess of Marlborough. Perhaps the greatest British general of all time and the most successful in the modern world until the advent of Napoleon, John Churchill, the first Duke of Marlborough, was also a successful if devious politician. He was a commanding figure, both on the continent of Europe and at the English court, from the time of King James II - whose mistress was Churchill's sister - until that of Queen Anne - whose intimate friend, the beautiful, gifted, quarrelsome Sarah, was his wife. The book concentrates on the Churchills' personal lives, telling the story of one of the 18th century's most powerful couples.