Ray, Iran, as a military objective

This article concerns the city of Ray, Iran (near Shahr-e-Rey) as a military objective, not the large territory of which it was once capital ("Ragau" in the Apocryphal Book of Judith). Ray, in an area of fertile lowland between the Zagros Mountains, the Elburz Mountains, and the great Dasht-e Kavir desert, commanded vital routes across and around the mountains, and was a key to power over the whole of Persia (Iran). The vast majority of ancient Persian literature has been lost, so little is known about the history of Ray before the arrival of Islam in the 7th century CE (although it is worth noting here that it was one of the great centres of the Zoroastrian religion).