The Mauryan empire encompassed most of the Indian subcontinent from the end of the 4th century BCE to the beginning of the 2nd century BCE. Candragupta Maurya, the founder of the dynasty, took control away from the Nanda dynasty that had ruled Magadha (modern southern Bihar in northern India) from their capital in Pataliputra (modern Patna). According to Indian literary traditions, Candragupta Maurya became ruler with the aid of Kautilya (or Canakya), a Brahmin minister traditionally credited with the authorship of the Arthasastra, a Sanskrit manual on statecraft. Eyewitness accounts of political, social, economic, and religious life in northern India during the Mauryan period are preserved in the fragmentary records of Megasthenes, a Seleucid ambassador to the Mauryans. When Candragupta Maurya relinquished control to Bindusara around 297-8 BCE, his dominion reached from the Ganges-Yamuna valley to the northwestern frontiers of the Indian subcontinent. Bindusara further extended the boundaries of the Mauryan empire to the Deccan peninsula of southern India before dying in 272 BCE.
The Mauryan empire reached its zenith during the reign of Asoka (ruling ca. 268-232 BCE). Asoka's inscriptions on stone monuments have been found in northwestern Pakistan and eastern Afghanistan, western India (Gujarat and Maharashtra), southern India (Karnataka and Andhra Pradesh), and eastern India (Orissa), demonstrating a network of administrative control radiating outwards from Pataliputra. These inscriptions were written in various dialects of Prakrit vernaculars, and are the earliest examples of writing in the Brahmi and Kharosthi scripts. Bilingual translations in Greek and Aramaic at Kandahar and Aramaic inscriptions in eastern Afghanistan illustrate the importance of promulgating his messages to the borderland inhabitants in their own languages. Sets of major and minor rock edicts, inscriptions on polished sandstone pillars, and inscriptions in caves record public proclamations of Asoka's moral and administrative policies, declarations to the Buddhist community (sangha), and donations to the Ajivikas (another heterodox community that received Mauryan patronage). The conquest of Kalinga (modern Orissa) in the eighth year of his reign caused Asoka to express great remorse in the thirteenth major rock edict. In that edict, he proclaims to his offspring and subjects that they should "consider the conquest of Dharma the real conquest." Asoka goes on to implore the people and ministers of his realm to live and govern according to the principles of Dharma, which in his view include the ideals of non-violence, religious tolerance, and respect for parents, teachers, and elders.
Although the policies of Dharma outlined in Asokan inscriptions do not correspond precisely to Buddhist doctrines, Asoka declared himself an ardent lay patron of Buddhism who personally visited several pilgrimage places linked with events in the life of the historical Buddha. Buddhist texts provide many illustrations of Asoka's role in giving donations to the Sangha, redistributing the Buddha's relics, and calling the third Buddhist council at Pataliputra. With Asoka's support, Buddhist missionaries (according to Pali texts, these included his son Mahinda and daughter Samghamitta) expanded the network of Buddhist monastic institutions throughout the Mauryan empire and in Sri Lanka, Kashmir, Gandhara, and the Swat Valley. Archaeological remains of stupas and monasteries established during the Mauryan period show that Buddhist centers in these regions functioned as bases for the transmission of Buddhism to Southeast Asia and Central Asia.
The succession of Mauryan rulers after Asoka is not certain, since genealogies recorded surviving texts differ. According to the Divyavadana, a Buddhist Sanskrit text, Asoka's immediate successor Kunala did not rule; rather, it was his son Samprati (who is known in Jain literature as a great patron) who became the Mauryan emperor. The last Mauryan ruler according to Puranic sources was Brihadratha, who was overthrown around 185 BCE by Pusyamitra, the founder of the Shunga dynasty. Although the Mauryan empire disintegrated within fifty years after Asoka's death, his legacy is preserved in his many inscriptions (which are indispensable for understanding ancient Indian history), mention in numerous literary traditions (including Sanskrit, western classical sources, and Tibetan and Chinese Buddhist texts), and in Mauryan artistic traditions, which produced the lion capital on the Asokan pillar at Sarnath, now the official seal of the government of modern India.