Tostig appears to have governed in Northumbria with some difficulty. He was never popular with the Northumbrian ruling class, a mix of Danish invaders and Anglo Saxon survivors of the last Norse invasion. Tostig was said to have been heavy handed with those who resisted his rule, including the murder of several members of leading Northumbrian families. In late 1063 or early 1064, Tostig had Gamal, son of Orm and Ulf, son of Dolfin, assassinated when they visited him under safe conduct.
[2] Also, the
Vita Edwardi, otherwise sympathetic to Tostig, states that he had 'repressed [the Northumbrians] with the heavy yoke of his rule'.
He was also frequently absent at the court of King Edward in the south, and possibly showed a lack of leadership against the raiding Scots. Their king was a personal friend of Tostig, and Tostig's unpopularity made it difficult to raise local levies to combat them. He resorted to using a strong force of Danish mercenaries (housecarles) as his main force, an expensive and resented policy (the housecarles' leaders were later slaughtered by rebels). Local biases probably also played a part. Tostig was from the south of England, a distinctly different culture from the north, which had not had a southern earl in several lifetimes. In 1063, still immersed in the confused local politics of Northumbria, his popularity apparently plummeted. Many of the inhabitants of Northumbria were Danes, who had enjoyed lesser taxation than in other parts of England. Yet the wars in Wales, of which Tostig's constituents were principal beneficiaries, needed to be paid for. Tostig had been a major commander in these wars attacking in the north while his brother Harold marched up from the south.
On 3 October 1065, the
thegns of Yorkshire and the rest of Yorkshire descended on York and occupied the city. They killed Tostig's officials and supporters, then declared Tostig outlawed for his unlawful actions and sent for
Morcar, younger brother of
Edwin, Earl of
Mercia. The northern rebels marched south to press their case with King Edward. They were joined at Northampton by Earl Edwin and his forces. There, they were met by Earl
Harold, who had been sent by King Edward to negotiate with them and thus did not bring his forces. After Harold, by then the king's right hand man, had spoken with the rebels at Northampton, he likely realized that Tostig would not be able to retain Northumbria. When he returned to Oxford, where the royal council was to meet on 28 October, he had probably already made up his mind.
Harold Godwinson persuaded the
King Edward the Confessor to agree to the demands of the rebels. Tostig was outlawed a short time later, possibly early in November, because he refused to accept his deposition as commanded by Edward. This led to the fatal confrontation and enmity between the two Godwinsons. At a meeting of the king and his council, Tostig publicly accused Harold of fomenting the rebellion. Harold was keen to unify England in the face of the grave threat from William of Normandy, who had openly declared his intention to take the English throne. It was likely that Harold had exiled his brother to ensure peace and loyalty in the north. Tostig, however, remained unconvinced and plotted vengeance.
Tostig took ship with his family and some loyal thegns and took refuge with his brother-in-law, Count Baldwin V. He even attempted to form an alliance with William. Baldwin provided him with a fleet and he landed in the Isle of Wight in May 1066, where he collected money and provisions. He raided the coast as far as
Sandwich but was forced to retreat when King Harold called out land and naval forces. He moved north and after an unsuccessful attempt to get his brother Gyrth to join him, he raided
Norfolk and
Lincolnshire. The Earls Edwin and Morcar defeated him decisively. Deserted by his men, he fled to his sworn brother, King
Malcolm III of Scotland. Tostig spent the summer of 1066 in Scotland.
He made contact with King
Harald III Hardrada of Norway and persuaded him to invade England. One of the sagas claims that he sailed for Norway, and greatly impressed the Norwegian king and his court, managing to sway a decidedly unenthusiastic Harald, who had just concluded a long and inconclusive war with Denmark, into raising a levy to take the throne of England. With Hardrada's aid, Tostig sailed up the
Humber and defeated Morcar and Edwin at
Gate Fulford.
