Explanation: The defining event of Ashoka’s rule was his campaign against Kalinga (present-day Odisha) in the eighth year of his reign.

The campaign had probably been more ferocious and brutal than usual because this was a punitive war against Kalinga, which had broken away from the Magadha Empire (the Hathigumpha inscription speaks of Kalinga as a part of the Nanda Empire).

Source: Tamil Nadu NCERT