The conversion to Judaism of the kingdom of Adiabene (in the upper Tigris region, modern–day northern Iraq), initiated by Queen Helena and her son Izates, marks the apogee of Jewish proselytizing in the Second Temple period both in the Parthian East and in the Greco–Roman world.
(Eli Barnavi, A Histrorical Atlas of the Jewish People. New York: Schocken Books, 1992)