Bjorn Ironside: The Son of Viking King, Ragnar Lothbrok

With a legacy of fierce battles, legendary expeditions, and a powerful lineage, Bjorn Ironside is easily one of the most captivating figures of the Viking Age.

As the son of the great Viking king Ragnar Lothbrok, Bjorn was destined for greatness from birth. But it was his skill, courage, and cunning that made him a fearsome warrior and an astute leader.

Whether he was leading the Great Heathen Army in its conquest of England alongside his Viking brothers, or raiding the coasts of the Mediterranean like few other Vikings before him, Bjorn left a permanent mark on the world of the Vikings and beyond.

Bjorn’s Viking Lineage and Family

Bjorn Ironside was born into a prominent Viking family sometime in the 9th century. Sources report that he was alive and conquering between 855 and 858. However, little else is known about the exact dates of birth and death. 

Bjorn was the son of the infamous Viking king, Ragnar Lothbrok, and Princess Aslaug. He was not the eldest son – his older brother was Ivar the Boneless. He had three other brothers, Hvitserk, Ubbe, and Sigurd Snake-in-the-Eye. He also had three half-brothers, Agnar and Eric from Thora, Ragnar Lothbrok’s first wife, and Fridleif, son of Lagertha and Ragnar. 

The Tale of Ragnar’s Sons, a famous Icelandic saga, tells of Bjorn’s lineage and upbringing. In the saga, according to tradition, he and his brothers left their father Ragnar’s kingdom in Sweden at a young age. 

They set out to conquer the areas of Zealand, Reidgotaland, Gotland, Oland, and all the minor islands while their father was still alive. They eventually settled in Denmark at Lejre, with Ivar the Boneless as their leader.

Bjorn’s early life was filled with legendary exploits and adventures. His upbringing in a family of renowned warriors shaped his destiny as a fearsome Viking warrior and leader.

Ravaging the Frankish Kingdoms

Early sources of Viking history supply historians with a few clues to Bjorn’s many conquests. Matching historical figures from different written works can be challenging, even for those most familiar with Viking history.

Based upon evidence from sources such as the Annals of St Bertin and the Gesta Normannorum Ducum, Bjorn Ironside was not just a feared Viking warrior, but also a conqueror of the Frankish lands. 

After leaving his homeland of Denmark, Bjorn set out with a considerable fleet and began raiding West Francia. He joined forces with another Viking named Sigtrygg and raided the inland areas of the Seine. 

Though they were defeated by Charles the Bald of West Francia in Champagne in 855, Bjorn received reinforcements and launched a successful assault on Paris in 856-857. They then constructed a fortification on the island of Oissel. 

Despite swearing fealty to Charles in 858, it’s unclear whether he kept his pledge. He continued to raid and plunder Paris with his Viking warriors. Despite Charles’ attempts to stop him, Bjorn held onto his stronghold of Oissel, which he used as the base of his operations for years.

Rumored Expeditions to the Mediterranean and Beyond

Like his expeditions into the lands of Francia, Bjorn’s forays into the Mediterranean are controversial and difficult to confirm. If the Norman history of William of Jumièges is to be believed, his conquests across Europe were nothing short of historic.

Along with Hastein, who is believed to be either one of Ragnar’s sons or a mentor assigned to him, Bjorn led a large Viking raid into the Mediterranean around 859-861. The raid also included Frankish, Norman, Arab, Scandinavian, and Irish forces.

The Norsemen sailed down along the Iberian coast, through Gibraltar. They pillaged the south of France before overwintering there. They then sailed to Italy, where they captured the city of Pisa.

During their Mediterranean expedition, the Vikings had many successful raids, through Sicily to North Africa. They also faced challenges. A storm once caused them to lose 40 ships. And a surprise attack by Andalusian forces left them with only 20 ships intact.

Björn’s most significant deed was the conquest of Luni, which the Vikings believed to be Rome at the time. Hastein devised a tricky plan to gain entry into the city. Once inside, the Viking party hacked its way to the town gates, which were promptly opened, allowing the rest of the army to enter.

When they realized that Luni was not Rome, Björn, and Hastein hoped to continue their streak of pillaging into the city, but balked when they learned of its potential fortifications.

Ragnar’s Death and the Tale of Ragnar’s Sons

Bjorn’s most famous legacy emerges from the Icelandic sagas – the Tale of Ragnar’s Sons and the Saga of Ragnar Lothbrok. They tell of Ragnar’s death at the hands of King Ælla of Northumbria, and how Ragnar’s sons sought revenge for their father. 

They formed the Great Heathen Army – an unrivaled Viking force. This was under the command of Bjorn’s brother, Ivar the Boneless. They sailed to England, looking to defeat Ælla.

From their base in York, the army marched on Northumbria. They defeated Ælla and took the kingdom for their own. However, the brothers would not be rid of their thirst for vengeance so easily.

Considering Ælla’s harsh murder of their father, they subjected him to a gruesome torture known as the blood-eagle before killing him. This involves cutting an eagle shape into Ælla’s back, severing his ribs from the backbone with a sword, and pulling out his lungs – a truly horrific practice.

Following their victory, the Vikings continued raiding throughout England, Normandy, and other parts of France. Bjorn received Uppsala and central Sweden, as well as all the lands that belonged to it, as his inheritance. 

He spent much of his time raiding in France before returning to his kingdom. There is no record of his death or any further mention of him.

Bjorn Ironside’s Lasting Legacy

Bjorn Ironside’s legacy is that of a legendary Viking warrior and conqueror. As the son of the great Viking king Ragnar Lothbrok, Bjorn was destined for greatness from birth. 

His skill, courage, and cunning made him a fearsome warrior and an astute leader, and his expeditions to the Frankish Kingdoms and the Mediterranean were nothing short of historic. 


Bjorn Ironside, Ragnar Lothbrok’s Son., 20 May 2019,

Grammaticus, Saxo. “Gesta Danorum, Book IX.” Project Gutenberg,

The Tale of Ragnar’s Sons. Translated by Peter Tunstall, 2005,

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