William II (floruit 1208–1252) was the Count of Geneva, originally a usurper, from 1225 until his death. He fought a long series of wars with the House of Savoy and lost control of all of his county outside of the traditional Genevois and saw his influence over the city of Geneva proper and the Bishop of Geneva severely reduced. William was the second son of Count William I of Geneva (died 1195) and younger brother of Count Humbert I of Geneva. When Humbert died in 1225, William seized the county and expelled Humbert's sons, his nephews, Peter and Ebal, who eventually found protection under Peter le Petit Charlemagne, who had brought them with him to England by 1244. That year Peter, the elder, married a rich English heiress, Mathilda de Lacy. Peter le Petit Charlemagne was in fact William's nephew, a son of his sister Margaret. In September 1229 at Tournon William was one of the arbiters of a dispute between the Bishop of Valence, William of Savoy, who was a brother of le Petit Charlemagne, and the citizens of Valence. In 1234 he had his second son, Amadeus, installed as a canon in the Diocese of Lausanne. In 1239 Amadeus was successful in leading the pro-Genevan party over he pro-Savoyard in the episcopal election which placed Jean de Cossonay on the bishop's seat. In 1236–37, Aymon, Baron of Faucigny, made himself protector of the priory of Chamonix despite the fact that the count of Geneva had a prior right. The ensuing war, in which Aymon's son-in-law, le Petit Charlemagne, was captured by William's son Rudolf, resulted in Genevan defeat, for on 13 May 1237 William II was forced to accept the judgement of Peter's brother, Amadeus IV, Count of Savoy, condemning him to an indemnity of 20,000 marks and the cession of the strategic Castle Arlod on the Rhône near its confluence with the Valserine, which commanded the approach to the Lyonnais. The sum of 20,000 marks was beyond William's ability to pay and the value of the fortress he was compelled to give up too high. The count of Geneva and Peter continued to be at war intermittently for the next five years. In 1242 William and le Petit Charlemagne fought a final brief war for control of Arlod. On 26 August, however, meeting his adversary "in front of Arlod", he was forced to cede it. In 1250