Ivar in The Sagas
He began as king of Scania and conquered Sweden by defeating Ingjald Illråde. He is then said to have conquered all of Scandinavia and parts of England. Because of his harsh rule, many Swedes fled west and populated Värmland under its king Olof Trätälja. His last campaign was in North Eastern Europe where he died, defeated by Odin in disguise. (Another source claims he took his life by drowning himself in the Gulf of Finland.)
According to both Ynglinga saga and Sögubrot, his homeland was Scania, but according to the Ynglinga saga, he had to flee Scania when his uncle Guðröðr of Scania had slain his father Halfdan the Valiant. The Ynglinga saga, Historia Norwegiæ, Hervarar saga and Upplendinga Konungum tell that Ivar conquered Sweden after Ingjald's suicide, and later returned to take Denmark.
According to Hversu Noregr byggðist and Njáls saga, he was the son of Halfdan the Valiant (also given as his father in the Ynglinga saga and the Hervarar saga), son of Harald the Old, son of Valdar, son of Roar (Hroðgar) of the house of Skjöldung (Scylding). According to Hversu, Njal's saga, the Lay of Hyndla and Sögubrot, Ivar had a daughter named Auðr the Deep-Minded.
Sögubrot relates that when Ivar was the king of Sweden, he gave his daughter Auðr the Deep-Minded to king Hrœrekr Ringslinger of Zealand, in spite of the fact that she wanted to marry Hrœrek's brother Helgi the Sharp. Hrœrekr and Auðr had the son Harald Wartooth. Ivar made Hrœrekr kill his brother Helgi, and after this, he attacked and killed Hrœrekr. However, Auðr arrived with the Zealand army and chased her father Ivar back to Sweden. The following year, Auðr went to Garðaríki with her son Harald and many powerful men and married its king Ráðbarðr. This was the opportunity for Ivar to conquer Zealand.
The Hervarar saga does not mention any daughter named Auðr. Instead it mentions an Alfhild. Ivar gave her to Valdar whom Ivar made subking of Denmark.
However, when Ivar learnt that Auðr had married without his permission, he marshalled a great leidang from Denmark and Sweden and went to Gardariki. He was very old at the time. However, when they had arrived at the borders of Raðbarð's kingdom, Karelia (Karjálabotnar), he threw himself overboard. Harald then returned to Scania to become its ruler. In the Lay of Hyndla, Ivar, Auðr, Hrœrekr and Harald appear. Raðbarðr also appears, but there is no information about his relationship with them.
Read more about this topic: Ivar Vidfamne