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 the 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. Today, the term Aran is mainly used in Azerbaijan to indicate territories consisting of Mil and Mughan plains (mostly, Beylaqan, Imishli, Kurdamir, Saatli, Sabirabad provinces of the Republic of Azerbaijan). It has also been used by Iranian historian Enayatollah Reza to refer to the country of Azerbaijan, freeing the name "Azerbaijan" to refer to a region within Iran. The bulk of the territory of the republic of Azerbaijan was the historic Shirvan, as well as Kuba/Qubbah). Etymology The region is known as Ardhan in Parthian, Al-Ran in Arabic, Aghvank or Alvank in Armenian, Rani () in Georgian and Caucasian Albania in Latin. According to the Albanian Movses Kagankatvatsi, Arran or Arhan was the name of the legendary founder of Caucasian Albania, who in some versions was the son of Noah's son Yafet (Japheth) and also, possibly the eponym of the ancient Caucasian Albanians (Aghvan), and/or the Iranian tribe known as Alans (Alani). The nearby Araks (Aras) river was known to Ancient Greek geographers as the Araxes, and has a source near Mount Ararat. James Darmesteter, in his discussion of the geography of the Avesta's Vendidad I, observes that the 12th century Bundahishn (29:12) identified the "Airyana Vaego by the Vanguhi Daitya" on the northern border of Azerbaijan, and did so "probably in order that it should be as near as possible to the seat of the Zoroastrian religion yet without losing its supernatural character by the counter-evidence of facts." Darmesteter further associated the Vanguhi Daitya river with the Araxes, and compared the name "Airyana Vaego" with that of Arran. According to C.E. Bosworth: {{cquote|The Georgians knew them [the Caucasian Albanians] as Rani, a form taken over in an Arabized form for the early Islamic geographical term al-Rān (pronounced ar-Rān).}} Later Greek writers also