Kalinga war was fought between the Mauryan king Ashoka and Kalinga. Ashoka the son of Bindusara and the grandson of Chandragupta Maurya is considered as the greatest ruler in the Indian History. War mostly is internecine to both sides but Kalinga war is historic because it made Ashoka from a brutal warrior to a follower of Buddhism.
Kalinga now parts of Odisha was a prosperous and economically developed state. During the time of Nandas, Kalinga was under the Magadha empire. The rise of Mauryan Empire saw the Kalinga became an independent state and from the time of Bindusara the Mauryas were trying to capture the Kalinga territory. When Ashoka rose to the throne of Mauryan Empire then it was the Golden period of Mauryan empire as the empire expanded and covered the most parts of India. Ashoka was so powerful that most empires surrendered to him, but Kalinga decided never to surrender and declared a war against the Mauryan Empire. Ashoka started the march with his army of around 400000 to Kalinga.
The war started in 261 BC which was Ashoka’s 8th year as the ruler of Mauryan Empire. It was an intense battle as around 3,00,000 people were killed and it is said that the river flowing in Kalinga had actually turned red. After watching all this carnage and blood shed, Ashoka had a change of heart and pledged that he will never go to war again with any Kingdom. Ashoka was a different king after this war, as he followed the path of ‘Ahimsa’ (Non-violence) and ruled with peace and prosperity for the rest of his life. Ashoka ruled for 36 years and propagated Buddhism everywhere. As per the legend when Ashoka died, his body burned for seven days and seven nights. How important is Asoka is evident from the fact that Ashoka chakra is a part of the Indian National flag.