William is a male given name of Germanic origin. It became very popular in the English language after the Norman conquest of England in 1066, and remained so throughout the Middle Ages and into the modern era. It is sometimes abbreviated "Wm." Shortened familiar versions in English include Will, Willy, Willie, Bill, and Billy.
Adolf, Duke of Jülich-Berg (c. 1370 – 14 July 1437), was the first Duke of the combined duchies of Jülich and Berg. He was the son of William VII of Jülich, 1st Duke of Berg and Anna of the Palatinate. In 1397, Adolf rebelled against his father along with his brother William, ravaged Düsseldorf and