Around 268 BCE Ashoka inherited the Mauryan throne his grandfather Chandragupta had founded; the empire then covered most of the Indian subcontinent, the eastern part of present-day Afghanistan, and reached the Bay of Bengal. Early in his reign Ashoka launched a major campaign against the independent eastern kingdom of Kalinga (c. 261 BCE). In his own words, a hundred thousand people died in the war and many more were deported. In Major Rock Edict XIII Ashoka writes that this loss caused him deep remorse, and that from then on he would speak not of military conquest but of 'conquest by Dhamma' — by moral persuasion, example, and service. It is the earliest known text in which an ancient ruler publicly indicts his own violence.

Ashoka's 'Dhamma' was not a narrow sectarian appeal. He clearly supported the Buddhist community — convening the Third Buddhist Council around 250 BCE and sending his son Mahinda as a missionary to Sri Lanka — but the edicts themselves emphasize a broad ethical framework: respect for all religions, obedience to parents, kind treatment of slaves and servants, restraint from needless killing of animals, and the provision of wells and medical care along the roads. Pillar Edict VII says he planted shade trees along pilgrimage routes and established physicians for both humans and animals.

The edicts reach the three ends of the empire. In the interior they use the Indic Brahmi script; in the northwest (today's Shahbazgarhi and Mansehra in Pakistan) the Aramaic-derived Kharoshthi; and near Kandahar, Greek and Aramaic. This multi-script, multilingual programme reflects both the empire's real extent and Ashoka's concern to address local populations in their own languages. Brahmi itself had been unreadable for centuries until James Prinsep deciphered Ashoka's inscriptions in 1837 — the king's name had stood on stone for two thousand years before anyone alive could read it.

The Mauryan state weakened quickly after Ashoka's death (c. 232 BCE) and broke apart within fifty years. But the influence of the edicts outlived the state. The missions Ashoka sent carried Buddhism to Sri Lanka, Central Asia, and from there to China and the rest of East Asia — a line of transmission that today connects more than half a billion Buddhists. When modern India declared independence it adopted as its state emblem the lion capital from the Ashoka pillar at Sarnath, and placed on its flag the Dhamma wheel that appears on the same pillars: a rare instance of moral discourse outlasting the empire that produced it.