Maurya Empire
"Beloved-of-the-Gods, King Priyadarsi(Ashoka)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 Dharma, a love for the Dharma and for instruction in Dharma. Now Beloved-of-the-Gods feels deep remorse for having conquered the Kalingas. "