Arran (Middle Persian form; Persian: ارّان), also known as Aran, was a geographical name used in ancient and medieval times to signify a historically-Iranian region which lay within the triangle of land, lowland in the east and mountainous in the west, formed by the junction of the Kura and Aras rivers, including the highland and lowland Karabakh, Mil plain and parts of the Mughan plain. In pre-Islamic times it 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.