 Although the Arsacid dynasty was of Iranian origin, it severed its relations with Persia when the rival Sassanid dynasty took over, and further when Armenia accepted Christianity in 301.While under Persian control, in 451, the battle of Vartanantz was fought by Armenians against the Persians in order to resist forced conversion to Zoroastrianism.Although a military defeat, the Persians afterwards allowed the Armenians to freely practice Christianity.