Battle of Kalinga (India) 261 BC
No war in the history of India as important either for its intensity or for its results as the Kalinga war of Ashoka. No wars in the annals of the human history has changed the heart of the victor from one of wanton cruelty to that of an exemplary piety as this one.
The war began in the 8th year of Ashoka's reign, probably in 261 BC. Ashoka's grandfather Chandragupta had previously attempted to conquer Kalinga, but had been repulsed. After a bloody battle for the throne after Bindusara's death, Ashoka tried to annex Kalinga. Ashoka was successful only after a savage war, whose consequences changed Ashoka's views on war and led him to pledge never to wage a war. It is said that in the aftermath of the Battle of Kalinga the Daya River running next to the battle field turned red with the blood of the slain; about 100,000 Kalinga civilians and more than 10,000 of Ashoka's own warriors were among those slain.