King Henry continued to support the young duke, but in late 1046 opponents of William came together in a rebellion centred in lower Normandy, led by Guy of Burgundy with support from Nigel, Viscount of the Cotentin, and Ranulf, Viscount of the Bessin. According to stories that may have legendary elements, an attempt was made to seize William at Valognes, but he escaped under cover of darkness, seeking refuge with King Henry. In early 1047 Henry and William returned to Normandy and were victorious at the Battle of Val-ès-Dunes near Caen, although few details of the actual fighting are recorded. William of Poitiers claimed that the battle was won mainly through William's efforts, but earlier accounts claim that King Henry's men and leadership also played an important part. William assumed power in Normandy, and shortly after the battle promulgated the Truce of God throughout his duchy, in an effort to limit warfare and violence by restricting the days of the year on which fighting was permitted. Although the Battle of Val-ès-Dunes marked a turning point in William's control of the duchy, it was not the end of his struggle to gain the upper hand over the nobility. The period from 1047 to 1054 saw almost continuous warfare, with lesser crises continuing until 1060.