Sigurðr hringr, Sigurd Ring (ca 750) was a Swedish king mentioned in sources such as the Heimskringla, Gesta Danorum, Hervarar Saga and Sögubrot af Nokkrum. He is of disputed historicity.
He was the nephew of the Danish king Harald Hildetand who put him on the Swedish throne. He beat his uncle at the colossal Battle of Bråvalla, and became the ruler of Denmark as well.
He ruled until he became very old. Then he fell in love with a beautiful girl, Alvsol of Vendsyssel, but was not allowed to marry her. Sigurd attacked Alvsol's brothers, but was mortally wounded during the battle. Alvsol had already died of poison so as not to be taken by Sigurd.
Sigurd had the girl and her brothers put on a ship which he steered out to the sea as the ship burnt.
He was the father of Ragnar Lodbrok.
