[1] William V was a key political figure of his time, being a brother-in-law to both Edward III of England and Emperor Ludwig IV.
He spent enormous sums of money to have his brother Walram of Jülich appointed as Archbishop of Cologne over Adolph II of the Marck.
Upon the collapse of the German-English alliance and the death of his brother-in-law, William switched his allegiance to Emperor Charles IV.
William won important positions through his Archbishop brother and also served for a time as a field captain for Flanders in the Hundred Years' War.
His sons fought against him during an uprising of part of the Jülich knighthood which opposed inclusion in the increasing territorial state, and he was imprisoned by them in 1349, but released in 1351 due to public pressure.