The Kingdom of Armenia was situated rather precariously between the two major imperial powers, Sassanid Persia and the Byzantines. Armenia was Christian, but had become a vassal of the Zoroastrian Sassanids. In 449, Yazdegerd II, the Sassanid king, believing their religion rendered the Armenians unreliable allies against their fellow Christians, the Byzantines, ordered their forcible conversion to Zoroastrianism. The Armenians promptly rose in revolt under the leadership of the military commander, Vartan Mamikonian. In May 454, the two armies faced one another on the banks of the Tghmout River. Although greatly outnumbered, and weakened by defections to the enemy, the Armenians held their own, with Mamikonian’s charge buckling the Sassanid left flank. But Niusalayourt, the Sasssanid general, then unleashed his elephants, breaking the Armenian lines, and Mamikonian was slain in the ensuing carnage. Despite defeat, Armenia continued to resist, and in 484, the Sassanids recognized their right to practise Christianity.
— OR —