On 25 November 1120 tragedy struck Henry I of England. His son, William Adelin was among the nobles who drowned when the White ship sunk in the English Channel. The loss of King Henry’s only legitimate son, changed William Clito’s fortunes. He was now the obvious male heir to England and Normandy. A significant party of Norman nobles took up his cause. Henry's problems became worse. His his son William Adelin had been promised in marriage to Matilda of Anjou, the daughter of Count Fulk V of Anjou. Fulk now wanted her dowry, including several castles and towns in Maine, returned. But Henry flatly refused. Fulk then promised his daughter Sibylla to William Clito, giving him the county of Maine as her dowry. King Henry then appealed to canon (Church) law and the marriage was eventually (not legal) in August 1124. The William and Sibylla were too closely related under Church laws of the time to be married.