William II (1307 – 26 September 1345) was Count of Hainaut from 1337 until his death. He was also Count of Holland (as William IV) and Count of Zeeland. He succeeded his father, Count William I of Hainaut. While away fighting in Prussia, the Frisians revolted. William returned home and was killed at the Battle of Warns.
Rotterdam (/ˈrɒtərdæm/ ROT-ər-dam, UK also /ˌrɒtərˈdæm/ ROT-ər-DAM; Dutch: [ˌrɔtərˈdɑm] ; lit. 'The Dam on the River Rotte') is the second-largest city in the Netherlands by population and the largest by area (319.4 km²). It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the New Meuse inland shipping channel, dug to connect to the Meuse at first and now to the Rhine.
Rotterdam's history goes back to 1270, when a dam was constructed in the Rotte. In 1340, Rotterdam was granted city rights by William IV, Count of Holland. The Rotterdam–The Hague metropolitan area, with a population of approximately 2.7 million, is the 10th-largest in the European Union and the most populous in the country.
The Battle of Warns (West Frisian: Slach by Warns; Dutch: Slag bij Warns) was a battle of the Friso-Hollandic Wars between Count William IV of Holland and the Frisians which took place on 26 September 1345. The annual commemoration of the battle is important for many nationalist Frisians. The Frisians won the battle and repelled the 'Hollanders' from the eastern coast of the Zuiderzee.