The Battle of Thermopylae in 267 was the unsuccessful defense of the pass by local forces during the great invasion of the Balkans by the Heruli. The Heruls are first mentioned by Roman writers in the reign of Gallienus (260-268), when they accompanied the Goths ravaging the coasts of the Black Sea and the Aegean. The mixed warbands managed to sack Byzantium in 267, but their eastern contingent was virtually annihilated in the Balkans at the Battle of Naissus (Serbia) two years later, the battle that earned Marcus Aurelius Claudius his surname "Gothicus."