Yrsa (Yrse)
Queen of Denmark and Sweden. In the Icelandic tradition, her name was Yrsa. In the Danish Gestuam Danorum (the history of Denmark that was written by Saxo), she was Vrsa, and in the Old English poem, Beowulf, she was called Yrse.
One thing that was inconsistent with Norse literature was that she was the daughter of Olof (or Alof), and Helgi (king of Denmark) was her father; Yrsa married both Adils and her father Helgi, but she didn't know that he was her father. By her father-husband, she was the mother of Hrolf.
In the Old English poem, Beowulf, she was not the daughter of Halga (Helgi), but of Healfdene (Halfdan), and she was the sister of Halga, Hrothgar and Heorogar. Also, she was not even the mother of Hrothulf (Hrolf), who was Halga's son. And she was not even married to Eadgils, who was the English equivalent of Adils; no, for according to Beowulf, she was married to Eadgils' uncle, Onela. So the Old English poem is quite confusing about how Yrsa was related to who in the Scylding (Skjoldung) line and to whom she was married to in the Swedish kingdom.
What is clear is that Yrsa (or Yrse) was known for her wisdom.
In the saga of Hrolf Kraki, Helgi raped Olof when she rejected him as being her suitor. So Olof became pregnant and gave birth to Yrsa. Yrsa was neglected as a child by her mother, and when Helgi met and fell in love with Yrsa, no one knew they were related except her mother. Olof didn't reveal that the married couple were father and daughter until Yrsa gave birth to Hrolf. The revelation that they had committed incest caused to Yrsa leave her father-husband and Denmark and return to her mother, only to have her mother arrange a marriage to a king whom she don't love - Adils, king of Sweden.
Adils came from the Yngling line. The new husband was known for his greed, cowadice and treachery. When Helgi came to demand tribute from Adils, Adils had his champions ambush Helgi. Her father-and-ex-husband's death earned Yrsa's enmity.
When Hrolf was king of Denmark, and came to Sweden to demand his mother's treasure as his rightful inheritance, she knew that Adils would treacherously try to kill her son, so she aided Hrolf's escape, plus helped him to gain the treasure. Adils pursued Hrolf and his champions, but stopped and dismounted his horse to pick up a gold ring, Adils' most prized treasure. With Adils bent down, Hrolf rode back and wounded the Swedish king, using his sword to cut Adils' buttocks.
When Hrolf and his champions were killed in battle against his half-sister Skuld (Yrsa's step-daughter, whom she had never met), and her husband Hiorvard, Yrsa raised an army under the command of Vogg who joined with the army of Bodvar's brothers, to avenge the heroes' death. They defeated Skuld and Hjorvard.
According to Ynglinga Saga, Snorri gives a different version of this legend. Adils married Yrsa first, after plundering Saxland. Helgi later took her away from Adils, and married her. To Helgi, she became the mother of Hrolf, the future king of Adils.
By Jimmy Joe