Cnut's invasion of Norway

Cnut's Invasion of Norway or Cnut's Conquest of Norway (Knuds invasion af Norge), was an invasion and subjugation of the Kingdom of Norway by the king of Denmark and England, Canute the Great between 1028 and 1029. The invasion was a success and did not encounter much resistance. Olaf Haraldson would flee to the Kievan Rus', and Cnut would be crowned king of Norway.

Background
Cnut's father and grandfather, Sweyn Forkbeard and Harald Gormsson, had previously had control in parts of Norway, particularly the area around Oslofjord. Additionally, circumstantial evidence supports that Sweyn Forkbeard held some form of overlordship over the Swedish king, Olaf Skötkonung. As a result of the Danish aggression in Scandinavia, Olaf Haraldson and Olaf Skötkonung made an alliance and attacked Denmark in 1026. After the seemingly inconclusive Battle of Helgeå, Cnut appears to have come out of the overall conflict with fewer losses than his counterparts. The Norwegians in particular, appear to have made a tactical error during the Battle of Helgeå. When the Swedes pulled out their forces to Svealand, Cnut and the Danes stationed their fleet at Øresund, hindering any Norwegian ships to return home. This resulted in the Norwegians abandoning their ships and marching through Sweden to reach Norway.

After this invasion, Cnut began to view his Norse neighbours as potential threats to his power. Subsequently, already in 1027, Danish envoys appeared throughout the Norwegian coast, bribing Norwegian aristocrats into going against Olaf Haraldson.

Invasion
In 1028, Canute was ready to strike Norway. With 50 ships, Cnut sailed along the Low German shores up to the Limfjord. The ships brought from England were large and well-manned. Olaf was informed of Cnut's fleet and intentions, and he did what he could to meet the invasion. The forces the Norwegians were able to muster, sailed up the Oslofjord and remained there until Cnut had departed from the land. Canute sailed across the Norwegian coasts, starting from Agder. At important points, Canute landed and summoned local assemblies. These assemblies generally obeyed Cnut, and the locals swore allegiance to their new king. However, wherever there was occasion to do so, Cnut appointed now local officials that he could trust.

Cnut spent some time in Egersund, where he renewed his alliance with Erling Skjalgsson, who joined him with a large force. When Trondheim (Nidaros) was reached, chieftains from all of Trøndelag were summoned to a grand assembly. Here Cnut was formally proclaimed the true King of Norway.

Aftermath
Notably, there was no reason for Cnut to go further north since representatives from the north were present in the grand assembly. Cnut installed Haakon Ericsson as governor of Norway, yet he would die at sea. Olaf Haraldsson now saw an opportunity to retake to throne, yet was defeated at Stiklestad. However, control over Norway was short-lived for Cnut, and dominion over the kingdom was lost within Cnut's lifetime, most probably in c. 1034.