A city in northeast India, founded as Pataliputra in the 5th century BC by Ajatashatru, king of Magadha. His son Udaya (Udayin) made it the capital of Magadha, which it remained until the 1st century BC. The second Magadha dynasty, the Maurya, ruled in the 3rd and early 2nd centuries BC until the city was sacked in 185 by Indo-Greeks. The Shunga dynasty followed, until about 73 BC. Pataliputra remained a center of learning and in the 4th century AD became the Gupta capital. It declined and was deserted by the 7th century. The city was refounded as Patna in 1541 and again rose to prosperity under the Mughal Empire. Part of the ancient city's rampart (reinforced with timber) and a large pillared hall survive. This hall, with its 80 pillars, has frequently been compared to similar halls found in Achaemenid Persia and it has been suggested that some Achaemenid craftsmen fled to India after the defeat of the Persians by Alexander the Great.