The First siege of Hatra by Ardashir I was an attempt at gaining the fortress of Hatra, which is about north-west of Baghdad.
The siege.
In c.226/c.229, the first Sasanian ruler, Ardashir I, besieged the city of Hatra, which may have been a Roman client kingdom.
The city's strong defenses, whose fortifications, according to archaeological evidence, reached 30 meters, resulted in a failure of this siege. Ardashir then marched to Media, where he succeeded in subduing its territories, and then to Armenia, where he was repulsed by Artabanus IV probably in 227–228.