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 in about 508, 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 which do not mention his name, in one of which Theoderic "adopted" him with a gift of arms. Less certainly, many scholars also equate him to the 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), while others were allowed to settle in a new kingdom under Roman controlled territory near present-day Belgrade.
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 a connection to this area. Some had lived in the region until they were driven out at some point in time by the Danes. However, Jordanes does not specifically connect Rodulf of the Rani to the Heruli. Procopius confirms that the Heruli had a connection to Scandinavia at least after the death of their king Rudolf, because he explains that some of the nobles who did not wish to come under Roman domination subsequently migrated there - leading some scholars to propose that these immigrants were the Heruli who the Danes expelled.
Another possible record of Rodulf of the Rani, and possibly of the Herules, is thus one of the surviving state papers of Theoderic which 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. Apart from the name Rudolf, the special allegiance to Theoderic is notable.
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.[1]
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.
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.