Flavus was a member of the royal family of the Germanic Cherusci tribe who served in the Roman military.
He is chiefly remembered as the younger brother of Arminius, who led the Germans to victory over the Romans at Teutoburg Forest in AD 9.
As an equite auxiliary, Flavus lost one of his eyes at the siege of Andetrium in AD 9 during the Illyrian Revolt.
Under Tiberius, he was involved in the Roman reprisal campaigns in Germany and he defeated his brother at Weser River.
Flavus seems to have died before AD 47 when the Cherusci are recorded appealing to Rome to send his son Italicus—the last surviving member of their royal family—to lead them.