Gesta Danorum
If the Chronicon Lethrense reports that the Swedes humiliated the Danes after Helghe's death, Saxo Grammaticus mentions nothing of this, but instead he has Helgo humiliate the Swedes in his Gesta Danorum, book 2. He also confused, or merged, Helgo with Helgi Hundingsbane, who in other sources is either a Völsung or a Geatish Wulfing (Ylfing). It is possible that it was the information that both killed a Hothbrodd and were called Helgi that inspired the merger.
Saxo agrees with Beowulf and the Chronicon Lethrense by describing Helgo and Ro (Hroðgar) as the sons of Haldanus (Healfdene). Like the Chronicon Lethrense, he relates that Ro and Helgo shared the kingdom after Haldanus' death (of old age), Ro taking the land, and Helgo the sea. Saxo adds that Helgo was a rather tall man.
Helgo attacked and killed king Skalk of Sklavia (i.e. the king of Wendland), subduing Sklavia into a Danish province. Continuing his sea roving, Helgo arrived at Thurø, where he found and raped the young girl Thora, which resulted in Urse.
He earned the name Hundingsbane by slaying Hunding, the king of Saxony, and conquered Jutland from the Saxons and entrusted it to his commanders Heske, Eyr and Ler. He then humiliated the Saxon aristocracy by enacting a law that the killing of one of them would be no more costly in wergild than the killing of a commoner.
When Helgo after many years returned to Thurø, Thora avenged her lost virginity by sending Urse to Helgo, who unknowingly raped his own daughter. This resulted in Roluo Kraki (i.e. Hroðulf).
Whereas the Chronicon Lethrense and the Annales Lundenses do not explain why Halga needed to kill Hodbrod to win all of Denmark, the Gesta Danorum presents Hothbrodd as a king of Sweden, who invaded Denmark and killed Ro. After having killed Hothbrodd, avenging the death of his brother, he humiliated the Swedes by forbidding that any crime against a Swede should result in any punishment by law. Then, hating his own country, he went east and died, reputedly by throwing himself onto his own sword. He was succeeded by his son Roluo.
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