Patna, on the southern bank of the Ganges at its junction with the Son, lies over the ancient city of Pataliputra. Though it is the capital of a state with more than eighty million people, it is a modest sized city in need of maintenance. There is little evidence of the past grandeur of Pataliputra, the greatest city of ancient India, except perhaps, at the Patna Museum where exquisite polished sandstone sculptures from the Mauryan period are exhibited. There is a faint glimpse of the ancient city about six kilometres from the train station, at Kumhrar, where excavations at a waterlogged site have revealed remnants of an eighty-pillared hall. Bihar has many developmental priorities to address before it can embark on excavations to uncover the lost city of Pataliputra beneath the several meters of alluvial laid down by the Ganges. Meanwhile, the magnificence of the city can be inferred from the accounts of the Greek ambassadors to the Mauryan court.

Megasthenese, the Greek ambassador at the court of Chandragupta Maurya, described the extent of Pataliputra as a parallelogram, 14 kilometres from east to west along the river and three kilometres from north to south. It was protected by massive timber palisades that were pierced by sixty-four gates and protected by watchful eyes from five hundred and seventy towers. The city exceeded the splendour of the Persian city of Susa and was, for that period, probably the greatest city in the world. A broad deep moat encircled the city serving both as a defensive barrier and as a sewer. In the year 321 BCE, in this city, Kautilya enthroned his protege Chandragupta Maurya as King of Magadha and India's first Emperor.

Kautilya was a Brahmin Jain from the South Indian village of Chanaka. Although endowed with a brilliant mind, he was hideously ugly and had deformities in his limbs. After studying at Taxila, he sought his fortune in Pataliputra, where his scholarship gained him the position of president of the Sangha, an assembly of academics. When he took the seat of honour at the royal court reserved for the president of the Sangha, presumably without the consent of the Nanda king, he was unceremoniously thrown out.