The defining feature of the next part of Norwegian history is strife and civil war. Political factions violently fought each other, kings and rulers were killed and overthrown, and the nation plunged into a spiritual civil war between the new religion of Christianity and the followers of older pagan beliefs.

READ MORE: A Viking history of Norway: Part 1

Fairhair and his not-so-fair sons

Harald I of Norway (often called Harald Fairhair) is often lauded as not only the first king of a united polity called "Norway" but also the founder of a dynasty that would, tradition states, last until the end of the 14th century CE. Somewhat surprisingly, for an early medieval monarch, Harald is said to have died of that most unnatural of causes (for the time) of old age in 933 CE. 

According to the Norwegian medieval "Grey Goose Laws," a ruler could not rule by himself after he (or, less commonly, she) turned 80 years of age. So, for the final two years of his life, he co-ruled with his favourite son and heir-elect, Erik Bloodaxe.

Though we know much about his father, little is known about the mysterious Erik Bloodaxe. According to various sagas, he travelled much in his youth, harrying coastal areas of the British Isles, France, Russia and Germany. 

He was supposed to have been chased out of Norway by some of his ambitious brothers and wound up ruling the Kingdom of Northumbria in modern-day England, and got mixed up with the political intrigues of the Norse, English and Irish throughout the British Isles. 

Though he reigned twice in Northumbria for a total of 7 years, he only sat on the Norwegian throne for 3. There is a scant historical record or contemporary sources of his reign in either kingdom. Eric was eventually forced to flee to the Orkney Islands and would die in battle in 954 CE.

Following Eric's demise, it was another of Harald's sons, Håkon the Good, that would take up the throne in 934 CE. Ruling for over 25 years, he is famous for his unsuccessful attempts at introducing Christianity to Norwegian societies. 

The Historia Norwegiæ, a short history of Norway compiled in the 12th century CE, claims that Håkon was an apostate whose tolerance of pagan rites as well as Christians damned his soul for eternity.

Eric's sons, however, wanted the throne back and set about a long period of invasions and war that would reach a crescendo at Fitjar in 961 CE. Though Eric's sons were finally defeated, Håkon was mortally wounded, and the crown passed to Harald Greycloack, who became Harald II. 

However, his assassination, after less than a decade on the throne, paved the way for external pressure and foreign influence.

Harald Bluetooth and foreign subjugation

Following the strife and political insecurity left by decades of assassinations, intrigues and violence, Norway became too sweet a prize to go unnoticed. 

Harald Bluetooth, King of Denmark, had spent the majority of his life battling and consolidating power in Jutland and Zealand to form a Danish kingdom. Following Harald Greycloak's assassination, Bluetooth saw his chance and pounced. 

He invaded Norway and forced the local population to accept his rule and reign. Though he is widely lauded in Denmark as uniting a warring bunch of tribes into a kingdom, overseeing the reconstruction of the Jelling stones and introducing Christianity into Denmark, his rule in Norway is often depicted as less benign.

Somewhat unsurprising for a man who had dominated Danish tribes and Dano-Norwegian politics for decades, Bluetooth's son, Sweyn Forkbeard (one of those marvellously descriptive Viking names, gotta love them!), also proved to be a bit of a handful. In the mid 980s CE, Sweyn revolted against his father, forcing him into exile, where he would ultimately die in the late 980s CE.

According to the later medieval historian Adam of Bremen, Sweyn, who became both King of Denmark and Norway, had all the moral failings of a pagan: he had betrayed his own father, persecuted Christians and expelled priests from Denmark. 

There is debate on the veracity of these claims, Adam was, after all, compiling his history for the Catholic Church, but it is a fact that he does indeed seem to have usurped power from his father.

Following Harald Greycloak's assassination, Harald Bluetooth invaded Norway. Photo: n_defender / Shutterstock

The making of an Empire

Yet Sweyn's route to power would be nothing but difficult. He had established a foothold in Norway as early as 970 CE, but a defeat on campaign in Francia saw him lose power to Olaf Tryggvason. 

Taking the royal name, Olaf I, Sweyn's successor, later oversaw the construction of the very first Christian church in Norway and founded the city of Nidaros (modern-day Trondheim).

Sweyn Forkbeard would have his ultimate revenge, however, at Svolder in the western Baltic Sea. Whilst Olaf I was returning from campaigns in modern-day Poland, a huge naval force under the command of Sweyn Forkbeard ambushed him. 

Forkbeard was readily helped by many of Olaf's enemies at home, angered by his pushy proselytizing and dogged determination on Christian conversion. The result saw Forkbeard gain the Norwegian throne again, and, not for the first time in its history, Norway was divided up and forced to cede sovereignty to both the Danish and Swedish royal courts.

Forkbeard's ascension to the throne seems to have caused a backlash against the relatively new religion of Christianity. Despite the fact there had been a Christian presence in Norway for centuries, it appears that Olaf's strong-handed techniques seemed to have alienated the population more than convinced them. 

Forkbeard would go on to invade England, seize the crown and form the "North Sea Empire" from 1013 to his death in 1015 CE. This empire, made up of the kingdoms of England, Denmark, and Norway, was perhaps the apogee of Norway's Viking power during the medieval period. 

Forkbeard, though not a Norwegian, ruled over an empire that was, in size and power, second only to the Holy Roman Empire in Western Europe.

Disintegration and decline

Forkbeard, who had forged a North Sea Empire encompassing Norse communities throughout the Danelaw in England and the various Anglo-Saxon kingdoms, joined with the Kingdoms of Denmark and Norway, would rule over this thalassocracy for a depressingly short time. 

Declared King of England, on Christmas Day, in 1013 CE, and by combining these three kingdoms, he would only rule for five weeks before his untimely death.

Upon Forkbeard's death, his empire would disintegrate and be divided between his sons, Cnut, Harald and the Anglo-Saxon kings, Æthelred the Unready and his son, Edmund Ironside. 

With Norway falling again to division and the rule of petty kingdoms, a power vacuum emerged. From one of the petty kingdoms, Viken, a new man would emerge whose ascension to power would signal the end of the Viking era of Norwegian history.

Forkbeard formed the North Sea Empire, which existed from 1013 to his death in 1015 CE. Photo: MARIOLA GROBELSKA / Unsplash

Olaf II and his demise

Though Olaf was born in the Ringerike district of western Norway, he spent much of his formative years away campaigning and battling throughout the Baltic region and the British Isles. 

He returned to Norway in 1015 CE and soon won the support of the five petty kings of the Norwegian north. He had been baptized on a campaign in Normandy and saw it as his divine mission to unite Norway. At the Battle of Nesjar in 1016 CE, he achieved this by defeating the last rebel earl who stood in his way. He spent the next decade consolidating his power at home and in the Orkney Islands.

Yet Olaf could not crush all dissent within his realm. Following a humiliating defeat at Helgeå, Norwegian earls seized their opportunity, drove Olaf into exile in the Kievan Rus and invited Forkbeard's son, Cnut the Great, to rule Norway. Biding his time, he slowly built up an army and prepared a military expedition to regain his throne.

According to contemporary sources, Olaf and his men, who were supported by Swedish king Anund Jacob, trekked through Sweden and crossed the mountains arriving 80 kilometers north of the city of Nidaros.

Writing two centuries later, Snorri Sturluson claims that Olaf faced a motley bunch of farmers sent out by the northern earls. Despite their lack of military prowess, this "Peasant's Army" was more than twice as large as Olaf's force. 

Tradition states that Olaf died in this battle, and his body was buried on the shores of the river Nidelva, just south of Trondheim.

A turning point in Norwegian history

Olaf II's death at the Battle of Stiklestad was not only one of the most famous battles in Norwegian history but also a turning point. A year after the battle, his body was moved from its riverside grave and moved to St. Clement's Church in nearby Nidaros. 

However, according to legend, when his coffin was opened, his body was uncorrupted. He was canonised a year later and would become the patron saint of Norway. The route to his final resting place would become one of the most important pilgrimages in Northern Europe.

Following 1030 CE, Norway was now firmly a Christian European nation. The following century saw a period of stability and peace as yet unknown in Norway. An archdiocese was created at Nidaros in 1152 CE. What had started as a series of small, petty Viking rulers had transformed, by the mid-12th century CE, into the medieval kingdom of Norway, an important regional power.

Vikings would no longer leave the shores of Norway to raid, but the increasing role of mercantile trade would see Norwegian ships ply the Baltic, North and Norwegian Sea to sell their wares in Northern European ports. This would be the basis for the Hanseatic League established from the 13th century onwards.

Yet, following the cultural reach of Norway during the Viking era and the political stretch of the North Sea Empire, the latter medieval period would spell doom for Norway thanks to a microscopic parasite often found on vermin. That, however, is a story for another day…

Perhaps the best exhibition that highlights Norway's proud Viking history is found at the History Museum in Oslo. If you are unable to visit it in person, browse through a wealth of material on its website here.

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