The Sack of Singara was an investment of the Sasanian-held city of Singara by the Byzantine army under the command of the general Maurice. The Byzantines took the city and destroyed it. This operation was conducted during Maurice's Sasanian Campaigns.
Background
In 578, the newly appointed magister militum per Orientem, Maurice, invaded Sasanian territory in Mesopotamia, in retaliation for a raid on Byzantine territory by Tamkhosrow earlier that year. After a highly successful and destructive attack against Arzanene, Maurice split his army into two. He delegated one portion to his subcommanders, Cours and Romanus, who crossed the Tigris and devastated its eastern bank, while his own division progressed south with the likely intention of intercepting the Sasanian commander Mahbod (who had conducted a counter-incursion towards Constantina) and his army.
Sack of Singara
Maurice marched his own division into Beth Arabye, probably in pursuit of Mahbod, first capturing Sasanian-held Thannuris and then pillaging the region up to the fortified settlement of Singara. Theophylact provided a description of this position in the late 6th century. Singara was heavily fortified and the lack of water sources in its vicinity made it difficult for a besieging army to support itself.
In spite of these imposing defences, Mahbod appears to have withdrawn from Singara before the arrival of the Byzantines, fearing besiegement there by the larger Byzantine army, while possibly also having problems in sustaining his own army in the region. Maurice's men then defeated the Sasanian garrison left behind in a siege and captured Singara. The contemporary historian Menander detailed the sophisticated siege techniques employed by the Byzantine armies during the campaign, noting their expertise in constructing walls of circumvallation, mining operations, and extensive use of artillery. Following their victory, the Byzantines ravaged and destroyed the settlement. Maurice returned in triumph to Byzantine territory for the winter, after the successful campaigns of 578.