Rodulf was king of the Heruli kingdom on the Middle Danube in the period around 500, and possibly of Scandinavian origin. He died in a battle with the neighbouring Lombards which led to the splitting up of the Heruli. He is probably the same Heruli king that Theoderic the Great wrote to in two surviving letters, in one of which Theoderic "adopted" him with a gift of arms. Less certainly, he is also sometimes equated to a King Rodulf that Jordanes mentions as having come from Scandinavia to Italy, to join Theoderic.
Rodulf was described by Procopius as the king of the Danubian Heruli already three years after the beginning of the reign of Emperor Anastasius (reigned 491-518). Paul the Deacon gave the same name for the Herul king who died when they were defeated by the Lombards, which is normally dated by historians to about 508. After this defeat Procopius reported that while some crossed the Danube into the Roman empire, another part of the Heruli nobility migrated north to the island of Thule (the name Procopius gave to Scandinavia). They passed through the lands of Sclavenes, Warini, and finally the Dani (Danes), before crossing Ocean and settling near the Gauti. He mentions that later generations of Heruli still living near the Danube successfully went to search for royalty in this region in the 540s.
It is uncertain but possible that this Rodulf is the same king of that name who is described in the Getica of Jordanes, as the king of the Ranii on the island of Scandza (what Jordanes called Scandinavia), who left his kingdom near the Danes, and came to Italy, where he succeeded in gaining the "embrace" (gremium) of the Ostrogothic King of Italy, Theodoric the Great. Notably, Jordanes mentions that the Heruli had also been living in this same general area, until they were driven out by the Danes, though his text does not connect this Rodulf to the Scandza Heruli.
The Scandza passage of Jordanes is subject to many different interpretations, and some historians have proposed that Jordanes made errors. For example, Theodor Mommsen believed Jordanes should have described the Scandinavian Rudolf as a Herul, and the historian Herwig Wolfram has described this Scandinavian Rudolf as a Gaut.
Due to the similarity of the circumstances, it has been suggested that the various accounts describe one individual, although this remains uncertain. Historians such as Andrew Merrill have pointed out that the similar elements in the accounts of Jordanes and Procopius may come from a common source, such as Cassiodorus, who worked for Theoderic.
Apart from the name Rudolf, the association with the region of the Dani, their apparent allegiance to Theoderic is notable. Another possible record of Rodulf is thus one of the surviving state papers of Theoderic shows that he adopted a Herule king (who is not named in that passage) as a "son in arms". The letter was made during the time of Cassiodorus's public service in the early 6th century, and is dated to 507-511.
More speculatively, another debated issue is whether Rodulf could be the inspiration for certain aspects of later heroic poetry, possibly including the Norse saga character Hrólfr Kraki.
King of the Heruls
The Herul kingdom was centred on Lower Austria and Moravia, north of the Middle Danube. It had existed there since 454, after the Battle of Nedao. Rodulf is the first known king of this kingdom, and the first mention of him which can be associated with a date is the remark of Procopius that implies he was ruling already in the early 490s. This was in the period after Theoderic the Great, took over the Kingdom of Italy from Odoacer. In Italy, Odoacer had been named as a king over the Heruli, and other Danubian peoples who had followed him there. After his murder in 493, the Herules still ruled a kingdom north of the Danube:
Procopius thus sees the conflict with the Langobards starting already in the 5th century, around 494. If however the un-named Herule king who was adopted by Theoderic was Rodulf, based on the idea that there was no Herule king after him who Theoderic would have allied to, then the letter announcing his adoption is estimated to be from 507-511, and the war can not have been earlier than that.
Jordanes also wrote about an unnamed king of the Heruli, who has been identified with Rodulf by some historians. He mentioned that Theodoric adopted a king of the Heruli as his "son in arms," by giving him a horse, sword and shield, probably around 507. The letter to the king, which was to be translated and explained by the envoys, stated that the king would "hold the first rank among the peoples."