Azimuntium (Azimus, or Esimontou) was a fortified town in Thracian region near the Illyrian border of the Eastern Roman Empire (present day Greece). The town is described by the Greek historian Priscus of Panium as the being the only one of the 182 forts and castles of Thrace to resist during the Attilan War of 443-446 A.D. and separately negotiating an exchange of captives with Attila after the peace was declared in 446 A.D.
The town is thought by Priscus to have still been in existence up the reign of the Emperor Justinian after which it "extirpated by the jealousy of the Roman princes". In Chapter 34 of his book "The history of the decline and fall of the Roman empire", Gibbons describes the town as follows:
The firmness of a single town, so obscure that except on this occasion it has never been mentioned by any historian or geographer, exposed the disgrace of the emperor and empire. Azimus, or Azimuntium, a small city of Thrace on the Illyrian borders, had been distinguished by the martial spirit of its youth, the skill and reputation of the leaders whom they had chosen, and their daring exploits against the innumerable host of the barbarians. Instead of tamely expecting their approach, the Azimuntines attacked, in frequent and successful sallies, the troops of the Huns, who gradually declined the dangerous neighbourhood, rescued from their hands the spoil and the captives, and recruited their domestic force by the voluntary association of fugitives and deserters.