Arran (Middle Persian form), also known as Aran was a geographical name used in ancient and medieval times to signify an Iranian region which lay within the triangle of land, lowland in the east and mountainous in the west, formed by the junction of Kura and Aras rivers, including the highland and lowland Karabakh, Mil plain and parts of the Mughan plain, and in the pre-Islamic times, corresponded roughly to the territory of modern-day Republic of Azerbaijan. The term is the Middle Persian equivalent to the Greco-Roman "Albania". It was known as "Aghvania", "Alvan-k" in Armenian, and "Al-ran" (Arabized form of "Arran") in Arabic.