The Siege of Amida took place when the Sassanids (Persian: ساساني‎‎), under Shah Shapur II (Persian: شاپور دوم‎‎) besieged the Roman city of Amida in 359.In this battle Ammianus Marcellinus, a historian of Greek origin from Antioch, was a Roman army officer; he described the siege in his work (Res Gestae).