The Usurpers tests King Stephen's title

The book compares rulers including William the Conqueror, Stephen, Henry IV, Edward IV, Richard III and Henry VII. The selected chapter asks whether Stephen fits the definition of a usurper. Although English succession lacked a rigid statute, Henry I had named Matilda as his heir and required the barons, including Stephen, to swear loyalty to her. Stephen's seizure of the crown helped produce the long civil conflict known as the Anarchy and failed to create secure rule. The book's conclusion rests on the distinction between customary preference for a male heir and the legal or sworn basis for Stephen's own claim.