The battle of Kalinga (now Orissa) became a turning point in the life of 'Asoka the Great'. The exact reason for the battle is not known. However, it is believed that one of Ashoka's brothers took refuge at Kalinga and this enraged Asoka, who launched a brutal assault on the province. The whole of the province was plundered and destroyed and thousands of people were killed.
It is said that after the battle of Kalinga was over, King Asoka went on a tour of the city. He could see nothing except burnt houses and scattered corpses. This was the first time in his life that Emperor Ashoka realized the consequences of wars and battles. It is said that even after he had returned to Patliputra, he was haunted by the scenes he saw in Kalinga. Even his queen, Devi, who was a Buddhist, left him after seeing the brutality at Kalinga.
It was during this time that he embraced Buddhism under the Brahmin Buddhist sages, Radhaswami and Manjushri. After adopting Buddhism, Asoka started propagating its principles throughout the world, even as far as ancient Rome and Egypt. Infact, he can be credited with making the first serious attempt to develop a Buddhist policy.
The third council of Buddhism was held under the patronage of Emperor Ashoka. He also supported the Vibhajjavada sub-school of the Sthaviravada sect, now known as the Pali Theravada.
After ruling over the Indian subcontinent for a period of approximately 40 years, the Great Emperor Asoka left for the holy abode in 232 BC. After his death, his empire lasted for just fifty more years.