Beloved-of-the-Gods, King Piyadasi, conquered the Kalingas eight years after his coronation. One hundred and fifty thousand were deported, one hundred thousand were killed and many more died (from other causes). After the Kalingas had been conquered, Beloved-of-the-Gods came to feel a strong inclination towards the Dhamma, a love for the Dhamma and for instruction in Dhamma. Now Beloved-of-the-Gods feels deep remorse for having conquered the Kalingas. Indeed, Beloved-of-the-Gods is deeply pained by the killing, dying and deportation that take place when an unconquered country is conquered. But Beloved-of-the-Gods is pained even more by this that Brahmins, ascetics, and householders of different religions who live in those countries, and who are respectful to superiors, to mother and father, to elders, and who behave properly and have strong loyalty towards friends, acquaintances, companions, relatives, servants and employees that they are injured, killed or separated from their loved ones. Even those who are not affected (by all this) suffer when they see friends, acquaintances, companions and relatives affected. These misfortunes befall all (as a result of war), and this pains Beloved-of-the-Gods. There is no country, except among the Greeks, where these two groups, Brahmins and ascetics, are not found, and there is no country where people are not devoted to one or another religion. Therefore the killing, death or deportation of a hundredth, or even a thousandth part of those who died during the conquest of Kalinga now pains Beloved-of-the-Gods. Now Beloved-of-the-Gods thinks that even those who do wrong should be forgiven where forgiveness is possible.

Ashoka the Great
Another Quote

The Power Of Failure: We Get To Decide What It Means