The Sanskrit name of modern Patna was Pataliputra. The city played an important role in the history of ancient India.
The name Pataliputra exists of the Sanskrit words patali (rice, a tree, or a stalk) and putra (son). As the settlement had originally been founded as Pataligrama (with grama meaning ''town''), the name Pataliputra could also be a transformation of Patalipura (with pura meaning ''town'' as well). The Greek ambassador Megasthenes, who visited the city, called it Palibothra, a name which would be picked up by other Greco-Roman scholars, like Arrian and Strabo.
Pataliputra is first mentioned in the Pali Canon and the Agamas, both early Buddhist texts, in which it is denoted as a small village. In the 6th century BCE, Bimbisara, the king of Magadha, fortified the village; actual urban development would start in the 4th and 3rd centuries BCE. Due to its strategic and favourable position, the young city became the capital of several successive north east Indian dynasties, a tradition which would endure well into the Early Middle Ages. After the death of the Buddha, the first two Buddhist councils were held in the city. Under the emperors Chandragupta and Ashoka, Pataliputra would become the capital of the mighty Mauryan Empire, which encompassed almost all of India. Under the Buddhist emperor Ashoka's reign, the city is estimated to have had a population of 150,000-400,000.
Although the great river Ganges now flows north of the site of the original city, its course laid more to the east in ancient times. It would meet with the ancient river Shona, known by the Greeks as Erannoboas, southeast of the city, creating a highly defensible natural moat on the southern and eastern sides of Pataliputra. The typical pillar design, known as the Pataliputra capital, was inspired by Persian and especially by Greek architecture. Strabo mentions that Pataliputra's walls were made of wood.