Norman rule, however, proved unstable; successions to the throne were contested, leading to violent conflicts between the claimants and their noble supporters. William II inherited the throne but faced revolts attempting to replace him with his older brother Robert or his cousin Stephen of Aumale. In 1100, William II died while hunting. Despite Robert's rival claims, his younger brother Henry I immediately seized power. War broke out, ending in Robert's defeat at Tinchebrai and his subsequent life imprisonment. Robert's son Clito remained free, however, and formed the focus for fresh revolts until his death in 1128. Henry's only legitimate son, William, died aboard the "White Ship" disaster of 1120, sparking a fresh succession crisis: Henry's nephew, Stephen of Blois, claimed the throne in 1135, but this was disputed by the Empress Matilda, Henry's daughter. Civil war broke out across England and Normandy, resulting in a long period of warfare later termed the Anarchy. Matilda's son, Henry, finally agreed to a peace settlement at Winchester and succeeded as king in 1154.