Siege of Petra
548 CE.
Shown on the map at 41.768°, 41.753°.
The siege of Petra took place in 549, when the Eastern Roman (Byzantine) Empire, under Emperor Justinian I, besieged the strategic fortress of Petra in Lazica, held by the Sasanians. Petra's garrison took heavy casualties, but stood firm until the arrival of a strong army under Mihr-Mihroe relieved the siege.
Text from the Wikipedia article Siege of Petra (549), licensed CC BY-SA 4.0.