King Ashoka began his reign by aggressively expanding his Mauryan Empire through conquest. However, after a particularly bloody battle in Kalinga where over 150,000 soldiers and civilians were killed, he was struck by the brutal consequences of war and adopted a policy of non-violence. He converted to Buddhism and sent missionaries to spread the teachings of Buddha. Ashoka built many Buddhist monuments and is remembered as a philosopher-king who established a period of peace and prosperity in India.