General Notes

The twentieth king of the Yngling dynasty in Sweden was said to be Adil.  This legendary monarch was married to Yrsa, the daughter of King Helge of Denmark.  Yrsa, although Helge's daughter, had also been his lover and had born him a son name Rolf, who later became king of Denmark. 

There was, predictably, a great deal of jealousy and fighting between Adil of Sweden and Helge of Denmark.  In the end, Helge was treacherously murdered by Adil.

Adil did not live long after this.  While at a great sacrifice in Uppsala, he died by falling from a horse, a death which was considered shameful.  Yrsa's son Rolf, on the other hand, died in battle, which was considered glorious.  Rolf's praises were then sung over all of Scandinavia.

(legends of early Swedish kings)  [Royal Families of Medieval Scandinavia, Flanders, and Kiev]