After this decision he released the prisoners of war and apologized to the nation. He left violence and became the follower of Buddhism.
Emperor Ashoka the Great (sometimes spelt Aśoka) lived from 304 to 232 BCE and was the third ruler of the Indian Mauryan Empire, the largest ever in the Indian subcontinent and one of the world's largest empires at its time. He ruled form 268 BCE to 232 BCE and became a model of kingship in the Buddhist tradition. Under Ashoka India had an estimated population of 30 million, much higher than any of the contemporary Hellenistic kingdoms. After Ashoka’s death, however, the Mauryan dynasty came to an end and its empire dissolved.
ASHOKA'S RULE
In the beginning, Ashoka ruled the empire like his grandfather did, in an efficient but cruel way. He used military strength in order to expand the empire and created sadistic rules against criminals. A Chinese traveller named Xuanzang (Hsüan-tsang) who visited India for several years during the 7th century CE, reports that even during his time, about 900 years after the time of Ashoka, Hindu tradition still remembered the prison Ashoka had established in the north of the capital as “Ashoka’s hell”. Ashoka ordered that prisoners should be subject to all imagined and unimagined tortures and nobody should ever leave the prison alive.
During the expansion of the Mauryan Empire, Ashoka led a war against a feudal state named Kalinga (present day Orissa) with the goal of annexing its territory, something that his grandfather had already attempted to do. The conflict took place around 261 BCE and it is considered one of the most brutal and bloodiest wars in world history. The people from Kalinga defended themselves stubbornly, keeping their honour but losing the war: Ashoka’s military strength was far beyond Kalinga’s. The disaster in Kalinga was supreme: with around 300,000 casualties, the city devastated and thousands of surviving men, women and children deported.
What happened after this war has been subject to numerous stories and it is not easy to make a sharp distinction between facts and fiction. What is actually supported by historical evidence is that Ashoka issued an edict expressing his regret for the suffering inflicted in Kalinga and assuring that he would renounce war and embrace the propagation of dharma. What Ashoka meant by dharma is not entirely clear: some believe that he was referring to the teachings of the Buddha and, therefore, he was expressing his conversion to Buddhism. But the word dharma, in the context of Ashoka, had also other meanings not necessarily linked to Buddhism. It is true, however, that in subsequent inscriptions Ashoka specifically mentions Buddhist sites and Buddhist texts, but what he meant by the word dharma seems to be more related to morals, social concerns and religious tolerance rather than Buddhism