Siege of Amida
359 CE.
Shown on the map at 37.917°, 40.217°.
The siege of Amida was a military investment of the Roman fortified frontier city of Amida (modern Diyarbakır, Turkey) by the Sasanian Empire. It took place in AD 359 when the Sasanian army under king Shapur II invaded the eastern provinces of the Roman Empire. Shapur wanted to exploit the absence of the Roman Emperor Constantius II who was overseeing affairs in the western part of the Empire. The city fell after a siege of 73 days.
Text from the Wikipedia article Siege of Amida (359), licensed CC BY-SA 4.0.