Territorial evolution of France face up to the formidable challenge with which they were presented. The Duke of Normandy William the Conqueror became King of England in 1066 through his victory at Hastings over the Saxons. On the extinction of his male line of descent, his heir was the Duke of Anjou, Henry Plantagenet, grandson by his mother of Henry I of England. Two months before he ascended to the English throne, as Henry II, he married Eleanor, Duchess of Aquitaine, the richest heiress in the French kingdom and ex-wife of the King of France. The kings of France nevertheless, held some trump cards:
William, Duke of Jülich-Cleves-Berg William, Duke of Jülich-Cleves-Berg William of Jülich-Cleves-Berge (William I of Cleves, William V of Jülich-Berg) (; 28 July 1516 – 5 January 1592) was a Duke of Jülich-Cleves-Berg (1539–1592). William was born in and died in Düsseldorf. He was the only son of John III, Duke of Jülich-Cleves-Berg, and Maria, Duchess of Jülich-Berg. William took over rule of his father's estates (the Duchy of Cleves and the County of Mark) upon his death in 1539. Despite his mother having lived until 1543, William also became the Duke of Berg and Jülich and the Count of Ravensberg. From 1538 to 1543,