By 585 B.C., the power of the Medes extended as far as the Halys River; they were thus in possession of the entire Arm. plateau and the former territories of Urartu. Median colonists probably settled in Armenia at that time, for the districts of Mardali and Mardastan attested in the Asxarhacoyc 'Geography' of the seventh century A.D. bear their name.