Bousas

According to chronicles written by Theophylact Simocatta around AD 630, a Byzantine soldier named Bousas was captured by the Avars at the Siege of Appiaria in 586 or 587. The Avar leader threatened to kill Bousas if his ransom were not paid. The citizens were either unwilling or unable to put up the money, yet Bousas, embittered by his countrymen's lack of helpfulness, saved his own life. He taught the Avars to make siege engines, and helped them capture the city.

Nothing is known Bousas' life, if he was indeed historical, beyond this one incident.

Bousas in Thessalonica
When Bousas was captured by the Avars, his commander refused to pay the ransom. It was believed that the commander was screwing Bousas' wife, or desirous of doing so. The embittered Bousas told the Avars how to build siege engines, and they captured the city. In 597, Avar siege engines were still a problem for Roman cities such as Thessalonica. Rufus, who told this story to George, had no idea what happened to Bousas' wife and her lover, but imagined it wasn't pretty.

Fortunately, the Avars who besieged Thessalonica were very poor siegecrafters, suggesting that they had never met Bousas.