Of what event or battle is that a depiction?
Do I perceive correctly that the British soldiers have the white-robed men tied to the front of the cannons?
Blowing someone to pieces from the mouth of a cannon was an oft-used punishment for treason in India and during part of the British rule there. That painting is from the aftermath of the Indian Rebellion of 1857, which finished off the old East India Company and brought in direct British rule of India.
}:-)4