During the later Achaemenid period, the Kassites, referred to as "Kossaei", lived in the mountains to the east of Media and were one of several "predatory" mountain tribes that regularly extracted "gifts" from the Achaemenid Persians, according to a citation of Nearchus by Strabo (13.3.6).
I den senere Achaemenidiske periode boede kassitterne, der blev omtalt som "Kossaei", i bjergene øst for Media og var en af flere "rovdyr" bjergstammer, der regelmæssigt udtog "gaver" fra de apeemeniske persere, ifølge et citat af Nearchus gengivet af Strabo (13.3.6).