In early January 1066, upon hearing of Harold's coronation, William began plans to invade England, building 700 warships and transports at Dives-sur-Mer on the Normandy coast. Initially, William struggled to gain support for his cause, however, after claiming that Harold had broken an oath sworn on sacred relics, the Pope formally declared William the rightful heir of the throne of England and nobles flocked to his cause. In preparation of the invasion, Harold assembled his troops on the Isle of Wight, but the invasion fleet remained in port for almost seven months, perhaps due to unfavourable winds. On 8 September, with provisions running out, Harold disbanded his army and returned to London. On the same day, the invasion force of Harald Hardrada, accompanied by Tostig, landed at the mouth of the Tyne. The invading forces of Hardrada and Tostig defeated the English earls Edwin of Mercia and Morcar of Northumbria at the Battle of Fulford near York on 20 September 1066. Harold led his army north on a forced march from London, reached Yorkshire in four days, and caught Hardrada by surprise. On 25 September, in the Battle of Stamford Bridge, Harold defeated Hardrada and Tostig, who were both killed. According to Snorri Sturluson, in a story described by Edward Freeman as "plainly mythical", before the battle a single man rode up alone to Harald Hardrada and Tostig. He gave no name, but spoke to Tostig, offering the return of his earldom if he would turn against Hardrada. Tostig asked what his brother Harold would be willing to give Hardrada for his trouble. The rider replied "Seven feet of English ground, as he is taller than other men." Then he rode back to the Saxon host. Hardrada was impressed by the rider's boldness, and asked Tostig who he was. Tostig replied that the rider was Harold Godwinson himself. Battle of Hastings On 12 September 1066 William's fleet sailed from Normandy. Several ships sank in storms, which forced the fleet to take shelter at Saint-Valery-sur-Somme and to wait for the wind to change. On 27 September the Norman fleet set sail for England, arriving the following day at Pevensey on the coast of East Sussex. Harold's army marched 241 miles (386 kilometres) to intercept William, who had landed perhaps 7,000 men in Sussex, southern England. Harold established his army in hastily built earthworks near Hastings. The two armies clashed at the