Rollo's descendant William, Duke of Normandy (the "Conqueror") became King of England after he defeated Harold Godwinson and his army at the Battle of Hastings in October 1066. As king of England, he retained the fiefdom of Normandy for himself and his descendants. The kings of England made claim to Normandy, as well as their other possessions in France, which led to various disputes with the French. This culminated in the French confiscation of Gascony that precipitated what became known as the Hundred Years' War, in 1337.