Why the brother of England's last Anglo-Saxon king led a foreign invasion against him.
Tostig Godwinson was a powerful Earl of Northumbria, yet his heavy-handed rule and tax policies turned his own people against him. After his brother, King Harold, orchestrated his exile, Tostig sought vengeance by aligning with a Norwegian king. Their fateful clash at Stamford Bridge changed the course of English history.
Tostig Godwinson, the third son of Earl Godwin, rose to prominence as the Earl of Northumbria in 1055. His governance was marked by intense friction. Unlike the local Northumbrian elite, Tostig was a southerner, and his reliance on expensive Danish mercenaries to maintain order alienated the local population. His administration was described as a heavy yoke, involving the assassination of prominent figures like Gamal son of Orm and Ulf son of Dolfin, which shattered his remaining support.
The breaking point arrived in October 1065, when Northumbrian thegns rebelled, demanding his removal. King Harold Godwinson, prioritizing national unity against the looming threat from William of Normandy, negotiated with the rebels and ultimately agreed to Tostig's deposition. This decision sparked a bitter, permanent enmity between the brothers. Tostig, feeling betrayed, spent the following months seeking alliances across Europe, eventually convincing King Harald Hardrada of Norway to launch an invasion of England.
In September 1066, the combined forces of Tostig and Hardrada invaded northern England, achieving an initial victory at the Battle of Fulford. However, their success was short-lived. King Harold marched his army north with remarkable speed, surprising the invaders at Stamford Bridge on 25 September 1066. The battle resulted in the deaths of both Tostig and Hardrada. While Harold emerged victorious, his forces were left exhausted and depleted, leaving them vulnerable to the Norman invasion that would defeat Harold just nineteen days later at the Battle of Hastings.
Source: Tostig Godwinson
