Background
He was the son of Floris IV and Matilda of Brabant. When his father was killed at a tournament at Corbie, William was only seven years old.
He was the son of Floris IV and Matilda of Brabant. When his father was killed at a tournament at Corbie, William was only seven years old.
He was elected as German anti-king in 1247 and remained king until his death. With the help of Henry II, Duke of Brabant and the archbishop of Cologne, he was elected in octobre 1247, at age 20, as king of Germany after Emperor Frederick II was excommunicated. The next year, he decided to extend his father"s hunting residence to a palace which met his new status.
This would later be called the Binnenhof (Inner Court) and was the beginning of the city of The Hague.
Meanwhile, after a siege of five months, William took Aachen from Frederick"s followers. Only then could he be crowned as king. his power never extended beyond the Rhineland."
In his home county, William fought with Flanders for control of Zeeland.
He made himself (being king of Germany) count of Zeeland. In July 1253, he defeated the Flemish army at Westkapelle (in modern-day Belgium) and a year later a cease-fire followed.
His anti-Flemish policy worsened his relationship with France.
From 1254, he fought a number of wars against the West Frisians. He built some strong castles in Heemskerk and Haarlem and created roads for the war against the Frisians. William gave city rights to Haarlem, Delft, "s-Gravenzande and Alkmaar.
In battle near Hoogwoud on 28 January 1256, William tried to traverse a frozen lake by himself, because he was lost, but his horse fell through the ice.
In this vulnerable position, William was killed by the Frisians, who secretly buried him under the floor of a house. William was then buried in Middelburg.
Contemporary sources, including the chronicle of Melis Stoke, portray William as an Arthurian hero.