 Although he wrote some generations later, one of his sources was the now lost "Historia Gothorum" ("History of the Goths") of Cassiodorus, who had written his account at the request of Theodoric the Great, King of the Ostrogoths and ruler of Italy.In the 19th century, the German classicist Theodor Mommsen argued that the Rodulf of the Ranii tribe and the Rodulf of the Heruli tribe constituted the same person.He proposed that Rodulf could have arrived to Theodoric in 489, when he was in Moesia.