The Nanda dynasty ruled in the northern part of the Indian subcontinent during the fourth century BCE, and possibly during the fifth century BCE. The Nandas overthrew the Shaishunaga dynasty in the Magadha region of eastern India, and expanded their empire to include a larger part of northern India. Ancient sources differ considerably regarding the names of the Nanda kings and the duration of their rule, but based on the Buddhist tradition recorded in the Mahavamsa, they appear to have ruled during circa 345–322 BCE, although some theories date the start of their rule to fifth century BCE. The Nandas built on the successes of their Haryanka and Shaishunaga predecessors, and instituted a more centralised administration. Ancient sources credit them with amassing great wealth, which was probably a result of introduction of new currency and taxation system. Ancient texts also suggest that the Nandas were unpopular among their subjects because of their low status birth, excessive taxation, and their general misconduct. The last Nanda king was overthrown by Chandragupta Maurya, the founder of the Maurya empire, and the latter's mentor Chanakya. Modern historians generally identify the ruler of the Gangaridai and the Prasii mentioned in ancient Greco-Roman accounts as a Nanda king. While describing Alexander the Great's invasion of north-western India (327–325 BCE), the Greco-Roman writers depict this kingdom as a great military power. The prospect of a war against this kingdom, coupled with the exhaustion resulting from almost a decade of campaigning, led to a mutiny among Alexander's homesick soldiers, putting an end to his Indian campaign. Origins Both Indian and Greco-Roman traditions characterize the dynasty's founder as of low birth. According to Greek historian Diodorus (1st century BCE), Porus told Alexander that the contemporary Nanda king was thought to be the son of a barber. Roman historian Curtius (1st century CE) adds that according to Porus, this barber became the former queen's paramour thanks to his attractive looks, treacherously assassinated the then king, usurped the supreme authority by pretending to act as a guardian for the then princes, and later killed the princes. The Jain tradition, as recorded in the Avashyaka Sutra and Parishishta-parvan, corroborates the Greco-Roman accounts, stating that the first Nanda king was the son of a barber. According to the 12th century text Parishishta-parvan, the mother of the first Nanda king was a courtesan. However, the text also states that the daughter of the last