In the 4th century, Geberic was succeeded by the Greuthungian king Ermanaric, who embarked on a large-scale expansion. Jordanes states that Ermanaric conquered a large number of warlike tribes, including the Heruli (who were led by Alaric), the Aesti and the Vistula Veneti, who, although militarily weak, were very numerous, and put up a strong resistance. Jordanes compares the conquests of Ermanaric to those of Alexander the Great, and states that he "ruled all the nations of Scythia and Germany by his own prowess alone." Interpreting Jordanes, Herwig Wolfram estimates that Ermanaric dominated a vast area of the Pontic Steppe stretching from the Baltic Sea to the Black Sea as far eastwards as the Ural Mountains, encompassing not only the Greuthungi, but also Baltic Finnic peoples, Slavs (such as the Antes), Rosomoni (Roxolani), Alans, Huns, Sarmatians and probably Aestii (Balts). According to Wolfram, it is certainly possible that the sphere of influence of the Chernyakhov culture could have extended well beyond its archaeological extent. Chernyakhov archaeological finds have been found far to the north in the forest steppe, suggesting Gothic domination of this area. Peter Heather on the other hand, contends that the extent of Ermanaric's power is exaggerated. Ermanaric's possible dominance of the Volga-Don trade routes has led historian Gottfried Schramm to consider his realm a forerunner of the Viking-founded state of Kievan Rus'. In the western part of Gothic territories, dominated by the Thervingi, there were also populations of Taifali, Sarmatians and other Iranian peoples, Dacians, Daco-Romans and other Romanized populations.