The Sasanian and the Roman Empire had since their peace treaty in 387 agreed that they both were obligated to cooperate in the defense of the Caucasus against nomadic attacks.[1] The Romans helped in the defense of the Caucasus by paying the Iranians roughly 500 lbs (226 kg) of gold at irregular intervals.[2] While the Romans saw this payment as political subsidies, the Iranians saw it as tribute, which proved that Rome was the deputy of Iran.[3] The Roman emperor Theodosius II's unwillingness to continue the payment made shah Yazdegerd II declare war against the Romans,[3][1] which had ultimately little success for either side.[4]