William II, Count of Hainaut was William IV of
Avesnes, William IV of
Holland and William III of
Zeeland from 1337, succeeding his father,
William I. He married
Joanna, Duchess of Brabant and Limburg in 1334.
William fought in
France as an ally of the
English (he was the brother-in-law of
Edward III). He went on crusade against the
Saracens and the
Lithuanians.
From 8 May to 22 June 1344 He besieged
Utrecht, because his one-time favourite bishop John van Arkel of Utrecht had turned against him, resulting in small teritorial gains for Utrecht and all lands of the Bsihopric become defact a protectorate of Holland, as it where before Bishop Jan van Arkel.
May 1345 Start of the conquest of the Frisianlands. The abby of Saint Odulphus reinforced as a Castle from were the comming years all frissian lands were conquerd. Castle Odulphus would be increased over time and was the first of what become a whole string of castles in Frisia as a mean to subject the Frisians.
By 1347 all Frisian lands recongnised William as their lord.
In order to pay this costly entreprise more towns were granted city rights or places already granted with city rights were able to extend their privileges, this included places in the recently subjected Frisian lands.
Representatives of several cities made part of the council of Hillegom, the hof of Holland.