[2] Martin immediately prepared a large force to capture the nearby Persian fort at Onoguris, expecting an easy victory.

According to Agathias, Martin and those behind the assassination of the Lazic king wanted to gain a success which could defuse a volatile situation in case Emperor Justinian I would notice their culpability.

[3] In 554 or 555, the Byzantine force of 50,000 fighting men under Martin besieged the Persian fort of Onoguris using wicker roofs (spaliones), ballistae, and other siege equipment.

As the Byzantine cavalry fled, the infantry was left behind, and the narrowness of the bridge over the Catharus River further hampered their flight, many of them being killed in the subsequent stampede.

[3] As the pursuing Persians reached Archaeopolis, they found the plain abandoned and momentarily demolished the Byzantine fortifications, looted their camp, and returned to the base.