The Early City: Bhir
After an early Achaemenid and Greek occupation of Bhir mound, the Mauryans took control of the city in 321 bce when it was conquered by Chandragupta Maurya. Chandragupta Maurya's son Bindusara and grandson Asoka both took special interest in the city. In fact, before Asoka became emperor of the Mauryan Empire, he was appointed viceroy of Taxila by his father. As is well known, with Emperor Bindusara’s death, Asoka ascended to the Mauryan throne in 274 bce and proceeded to bring much of the subcontinent under his control through violent means. After securing his empire, Asoka felt remorse for the suffering he had inflicted during his conquests and, as his Rock Edicts reveal, he converted to Buddhism. 
The nature of Asoka’s conversion and what it actually meant has been the subject of debate. But again, this essay is not meant to detail Asoka’s Buddhist beliefs. See Thapar, Asoka and the Decline of the Mauryas, pp. 137-181.
Bhir mound was eventually abandoned for a new site just up the Tamra Nala river, called Sirkap, at the end of the second century to the beginning of the first century bce.