Fritigern
Fritigern or Fritigernus (died ca. 380) was a Thervingian Gothic chieftain whose decisive victory at Adrianople during the Gothic War (376-382) led to favourable terms for the Goths when peace was made with Gratian and Theodosius I in 382.
Conflicts against Athanaric
Socrates Scholasticus, Sozomen, and Zosimus refer to conflicts between Fritigern and Athanaric.Ammianus Marcellinus and Philostorgius do not record such conflicts.
According to Socrates, Fritigern and Athanaric were rival leaders of the (Therving) Goths. As this rivalry grew into warfare, Athanaric gained the advantage, and Fritigern asked for Roman aid. The Emperor Valens and the Thracian field army intervened, Valens and Fritigern defeated Athanaric, and Fritigern converted to Christianity, following the same teachings as Valens followed. Sozomen follows Socrates' account.
According to Zosimus, Athanaric (Athomaricus) was the king of the Goths (Scythians). Sometime after their victory at Adrianople, and after the accession of Theodosius, Fritigern, Alatheus, and Saphrax moved north of the Danube and defeated Athanaric, before returning south of the Danube.