Alexander ( taxiarch ) Alexander was a Byzantine military officer , active in the reign of Maurice . He is styled a taxiarch ( ) in the accounts of Theophylact Simocatta . He is known for his part in campaigns against the South Slavs . Biography . Alexander is styled a taxiarch ( ) in the accounts of Theophylact Simocatta . This might be an attempt to translate a Latin title . He is unlikely to have served as a magister militum , always mentioned serving under other commanders . He might have been a comes rei militaris or a dux . In either case , Alexander was stationed in Thrace . He is first mentioned in 593 , serving under Priscus . Alexander was at that time tasked with leading a scouting party . He and his men crossed the river " Helibakion " ( Ialomiţa River ) in search of a group of Slavic raiders . The raiders attempted to escape through the local marshes , disorienting the Byzantines . Alexander attempted to set fire to the woods covering the rebels . But the material was too wet to catch fire . At that point , one of the raiders defected to Alexander ' s side . He was a Gepid who had briefly joined the Slavs , but apparently was not committed to their cause . He led Alexander to the hideout of his former allies . They were easily captured . Alexander returned to Priscus ' camp with the captives and valuable information . The raiders were spies employed by Musokios . The latter had just been informed of the defeat of Ardagast and had yet to react to it . Priscus and the defector started working on a trap to capture Musokios and his forces . In said plan , Alexander was assigned to lead an advance force . Late one night , Alexander and two hundred soldiers managed to take positions near the banks of the river Paspirion . They went unnoticed and lay in ambush . The following night , they attacked the boatmen of Musokios , who were reportedly drunk and asleep at the time . They were easily sloughtered . Alexander captured the entire fleet of the Slavs . The boats were used to transport Priscus and the main force of the army , an estimated 3 , 000 men . Under the cover of the night , the entire force attacked the Slavic camp . Musokios was captured alive , while most of his men were slaughtered . In 594 , Alexander served under the curopalates Peter . Alexander led a force of 1 , 000 cavalrymen against 600 Slavs . The enemies had recently plundered a number of cities in Moesia and were slowed down by the need to transport their loot . The Slavs reacted swiftly to Alexander ' s approach . They first executed all the male prisoners from Moesia who were able to use weapons . They then used their waggons as barricades , placing the female captives and the children in the middle . The warriors themselves " stood on the carts , brandishing their javelins " . The Byzantine cavalrymen could not approach their enemies without exposing their horses to danger . So Alexander ordered them to dismount and fight as infantry . The battle was decided when an unnamed Byzantine soldier managed to capture one of the waggons . The defense of the Slavs collapses , though they took the time to kill the rest of their captives first . They were then killed by the charging Byzantines . Following this victory , there is no further mention of Alexander .