before the
Siege of Amida of 359 AD, in which Grumbates participated. Ammianus himself was present in the city until a day before its fall. Grumbates thus participated in the
Siege of Amida in 359 AD as an ally of
Shapur II. His participation to the Sasanian campaign in the Eastern Caspian lands are described by Ammianus Marcellinus, who was inside the fortress of Amida at the time: The son of Grumbates, while inspecting the defences of Amida, was shot and killed with an arrow shot by the city garrison. Ammianus described how the Grumbates, outraged at his son's death, demanded revenge from the Romans: he compares the death to that of
Patroclus at
Troy. The Sassanids began the attack with
siege towers and attempted to take the city hastily, but were largely unsuccessful. Unable to gain a quick victory, Shapur II had to commit to capturing Amida in order to appease his ally Grumbates. ==References==