Battle of Svolder - Events Leading Up To The Battle

Events Leading Up To The Battle

Nothing can be gleaned from the contemporary skaldic poems on the causes of the battle. Adam of Bremen states that Olaf Tryggvason's Danish wife, Thyri, egged him on to make war against Denmark. When Olaf heard that Svein Forkbeard and Olaf the Swede had formed an alliance, he was angered and decided the time had come for an attack. Ágrip and Historia Norwegie have a similar account. Thyri was the sister of Svein Forkbeard, and when Olaf Tryggvason married her, Svein refused to pay her promised dowry. Angered, Olaf launched an expedition to attack Denmark, but he was too impatient to wait for a fleet to assemble from all of Norway, and he set sail for the south with only 11 ships, expecting the rest to follow. When that hope was not realized, he set out for Wendland (Pomerania) to seek allies and on the way was ambushed by Svein and his allies. These accounts are contradicted by a contemporary verse of Halldórr the Unchristian which states that Olaf Tryggvason was travelling from the south when he came to the battle.

Oddr Snorrason has an elaborate account of the problems arising from Thyri's marriages. He tells us that she was betrothed and married to the Wendish king Bolesław the Brave, who received a large dowry for her; but she did not want to be his wife and starved herself after their wedding, so Bolesław sent her back to Denmark. She then arranged to have herself married to Olaf Tryggvason, to the displeasure of her brother Svein. Svein's queen, Sigrid the Haughty, a staunch opponent of Olaf, egged Svein to make war on him. Svein then conspired with Jarl Sigvaldi and King Olaf of Sweden to lure Olaf Tryggvason into a trap. Olaf Tryggvason travelled to Wendland to collect Thyri's dowry from King Bolesław and while there heard rumours of a planned ambush; but Sigvaldi arrived to tell him these rumours were false. Believing Sigvaldi, Olaf sent most of his fleet home, as his men were impatient. He therefore had only a small fleet left when he was ambushed near Svolder.

Fagrskinna and Heimskringla largely follow Oddr's account but simplify it and diverge from it in some respects. According to Heimskringla, Sigvaldi sailed from Wendland with Olaf and a fleet of Wendish ships and led him into the ambush.

Whether the above details are accurate or not, it is clear that Svein, Olaf the Swede and Eirik had ample reason to oppose Olaf Tryggvason. Olaf had taken control of Viken in south Norway, an area long under Danish overlordship. Olaf and Svein had been in England together, but Olaf had made peace while Svein kept campaigning. Svein was on friendly terms with Olaf the Swede and connected to him by marriage, so the two were natural allies. Finally, Jarl Eirik had been driven from his patrimony by Olaf Tryggvason, as arguably had his father, Jarl Hakon, whom he may have wished to avenge.

From the conflicting accounts of the sources, historians have tried to reconstruct the most likely sequence of events leading up to the battle. It is probable that Olaf Tryggvason was indeed sailing from Wendland to Norway when he was ambushed, though the kings' sagas probably play up the importance of Thyri and her marriages. While it is possible that Olaf was collecting dowry, it seems more probable that he was expecting war and seeking allies in Wendland, but met with little success. The character of Sigvaldi remains enigmatic, though there is evidence from skaldic poetry that he did indeed betray Olaf.