Which historical conflict killed the most people?

World War II is considered the historical conflict that caused the most casualties, resulting in the deaths of approximately 70-85 million people. This devastating conflict, lasting from 1939 to 1945, involved major world powers and their allies, including Germany, Japan, and Italy, against the Allied forces. It encompassed both military combat and civilian deaths, with widespread destruction and loss of life due to bombings, massacres, and genocide. The war's scale, global reach, and the Holocaust's horrifying atrocities were pivotal factors contributing to the immense death toll, making World War II the deadliest conflict in history.