The Viking Invasion!
After waiting for sight of the Normans and losing his levies the desperate news then came of a Viking landing on a lightly defended part of the North East coast. There had been a defeat at York. The Viking forces were even greater than those expected from the Normans. Harold had no alternative but to move his army to defend his Kingdom from the Vikings.
He force-marched his Army to the North of England, on the old Roman road called "Watling Street". This destroyed King Harold's plans to deal with Duke William's invading force from Normandy.
Treachery! Earl Tostig plots with King Hardrada
The questions on Harold's mind must have been "What had provoked the Viking attack, and why now, when England was facing the threat of the Normans?" He soon found out! Harold's ambitious, renegade brother, Earl Tostig, had travelled to Norway and persuaded the Norse King to attack England.
Tostig was the son of Earl Godwin of Wessex, and brother of Harold, was born in about 1025. In 1051 Tostig married Judith, daughter of Baldwin IV, the count of Flanders. In 1055, King Edward the Confessor made Tostig the Earl of Northumbria, Northamptonshire and Huntingdonshire. Tostig's rule was tyrannical and in 1065 he was replaced by Morcar, Harold's brother-in-law. Tostig was banished from the country and fled to Flanders. Tostig then went to Normandy and offered to help Duke William against his brother. In May 1066 Tostig landed in the Isle of Wight and then sailed to the North of England but was defeated by Morcar. Tostig tried to involve King Sweyn of Denmark to fight against Harold and when he refused Tostig went to Norway to meet with King Hardrada.
King Harald Hardrada was keen to take the English crown and the combined forces of Harald Hardrada and Tostig were massive and believed to have totalled a formidable 10,000 men. (The Norman army numbered less than 7,000 men and the English force was originally 7000-8000 strong)
King Hardrada's fleet consisted of over five hundred ships, nearly half of which were warships, furthermore the best Norse warriors were with the fleet. He sailed first to the Orkneys, where he convinced many of the islanders to join him, and then on to Yorkshire.
The possibility of an attack from King Harald Hardrada had been totally eclipsed by the gathering invasion force of Duke William. The Norse attack was larger and more fierce than could ever have been expected, possibly the largest fleet to ever sail from the Scandinavian ports.
Earl Tostig with King Harald Hardrada and the Vikings must have felt totally confident in wining a victory! King Harold and his army were waiting on the South coast of England for the Normans, leaving the North of England vulnerable to the treacherous Earl Tostig, King Harald Hardrada and the Vikings!