Pataliputra, adjacent to modern-day Patna, Bihar, was a city in ancient India, originally built by Magadha ruler Ajatashatru in 490 BCE, as a small fort near the Ganges river. Udayin laid the foundation of the city of Pataliputra at the confluence of two rivers, the Son and the Ganges. He shifted his capital from Rajgriha to Pataliputra due to the latter's central location in the empire.