Heimskringla
In Chapter 5 of the Ynglinga saga section of his Heimskringla, Snorri Sturluson relates that Odin and the Æsir first arrived at Old Sigtuna when they came to Sweden:
- Odin took up his residence at the Maelare lake, at the place now called Old Sigtun. There he erected a large temple, where there were sacrifices according to the customs of the Asaland people. He appropriated to himself the whole of that district, and called it Sigtun. To the temple priests he gave also domains. Njord dwelt in Noatun, Freyr in Upsala, Heimdal in the Himinbergs, Thor in Thrudvang, Balder in Breidablik; to all of them he gave good estates.
Later the pirate Sölve arrived at Old Sigtuna to claim the Swedish throne:
- Solve came unexpectedly in the night on Eystein (Östen), surrounded the house in which the king was, and burned him and all his court. Then Solve went to Sigtun, and desired that the Swedes should receive him, and give him the title of king; but they collected an army, and tried to defend the country against him, on which there was a great battle, that lasted, according to report, eleven days. There King Solve was victorious, and was afterwards king of the Swedish dominions for a long time, until at last the Swedes betrayed him, and he was killed.
In the part called The Saga of St. Olaf, the Norwegian king Olaf Haraldsson makes shore at Old Sigtuna:
- King Olaf steered thereafter eastwards to Svithjod, and into the Lag (the Mælar lake), and ravaged the land on both sides. He sailed all the way up to Sigtuna, and laid his ships close to the old Sigtuna. The Swedes say the stone-heaps are still to be seen which Olaf had laid under the ends of the gangways from the shore to the ships.
Read more about this topic: Fornsigtuna