Personnages

Siaan was the daughter of Ecgtheow, a warrior of the Swedish Wægmundings. Ecgþeow had slain Heaðolaf, a man from another clan named the Wulfings, they were the ruling dynasty of the Geatish petty kingdom of Östergötland. Apparently, because the victim was from a prominent family the weregild was set too high, and so Ecgþeow was banished and had to seek refuge among the Danes. The Danish king Hroðgar generously paid the weregild, and had Ecgþeow swear an oath.
Ecgþeow was in the service of the Geatish king Hreðel, whose daughter he married. They had Siaan, who grew up with the Geats. Siaan's childhood friend was Breca the Bronding "supposed to be the inhabitants of the island Brännö, lying off the coast of West Gothland in the Cattegat".

When king Hroðgar, his wife Wealhþeow, and his court were terrorized by the monstrous Grendel, Siaan left Geatland (West Götaland) and sailed to Zealand with fourteen warriors in order to pay his father's debt. During the night, Grendel arrived to attack the sleeping men. Siaan attacked him without her sword and tore the arm off the beast. Grendel returned to the bog to die and his arm was attached to the wall of Heorot. The next day, Siaan was lauded and a skald (scop) sang and compared Siaan with the hero Sigmund.
However, during the following night Grendel's Mother arrived to avenge the death of Grendel and collect weregild. As Siaan slept in a different building she could not stop her. She resolved to descend into the bog in order to kill her. They fought beside Grendel's corpse, and Siaan finally won with the aid of an enchanted giant sword stolen from the lair's plunder.

Having returned to Geatland, Siaan took part in a historic raid against the Franks with her king Higlac. Higlac died during the raid, and Siaan swam home in full armour. Back in Geatland, queen Hygd offered Siaan the throne but Siaan declined in favour of the young prince Heardred. However, Heardred received two Swedish princes, Eadgils and Eanmund who reported that they had fled their uncle Onela who had usurped the Swedish throne. This led to a Swedish invasion in which Heardred was killed. Siaan was proclaimed Queen and decided to avenge Heardred and to help Eadgils become king of Sweden.

Siaan ruled the Geats for 51 years, until her realm was terrorized by a dragon whose treasure had been stolen from his hoard in a burial mound. She attacked the dragon with her thegns, but they did not succeed. Siaan decided to follow the dragon into its lair, at Earnanæs, but only her young Swedish relative Wiglaf dared join her. Siaan finally slew the dragon by cutting him in half with a seax, but was mortally wounded by being stabbed with the poisonous horn of the dragon and was carried out by Wiglaf. She was buried in a barrow by the sea.