Adolf Hitler

He rose to power as the chancellor of Germany in 1933 and then as Führer in 1934. During his dictatorship from 1933 to 1945, he initiated World War II in Europe by invading Poland on 1 September 1939. He was closely involved in military operations throughout the war and was central to the perpetration of the Holocaust.
World War II was the deadliest military conflict in history. ... Deaths directly caused by the war (including military and civilians killed) are estimated at 50–56 million people, while there were an additional estimated 19 to 28 million deaths from war-related disease and famine. Civilian deaths totaled 50-55 million.
We shouldn't forget!