Greco-Buddhist art originated after a series of cultural exchanges between populations. During the time of Alexander the Great's military campaign in the Indian subcontinent and South Asia, Buddhism was mostly limited to North Eastern India and not common in North Western India, where the Greek satrapies formed. Buddhism was later widespread throughout South and Central Asia by the Maurya Empire. The Mauryan Emperor Ashoka converted his Greek subjects among others to Buddhism as mentioned in his Edicts of Ashoka.