Answer
The Drevlians were a Slavic tribe that inhabited the territory of modern-day Ukraine and Belarus. They were known for their fierceness and their resistance to Kievan Rus' rule. In 945, Olga, the widow of Prince Igor of Kievan Rus', led a punitive expedition against the Drevlians in response to their murder of her husband. Olga burned their capital city to the ground and slaughtered many of their people.