One of the bloodiest battles in the Middle Ages took place near the town in 917 when the Bulgarian Emperor Simeon I delivered a devastating blow to the Byzantine army. More than 90,000 men perished in the battle, 70,000 of whom were Byzantines. In the decades following the Battle of Anchialus the Bulgarian Empire entered a period of upheaval and relished a territorial extent, covering most of the Balkan peninsula.