The Maurya Empire was a geographically extensive Iron Age historical power in South Asia with its power base in Magadha. Founded by Chandragupta Maurya around c. 320 BCE, it existed in loose-knit fashion until 185 BCE. The primary sources for the written records of the Mauryan times are partial records of the lost history of Megasthenes in Roman texts of several centuries later; and the Edicts of Ashoka. Archaeologically, the period of Mauryan rule in South Asia falls into the era of Northern Black Polished Ware (NBPW).