Sir Ian Kershaw is an English historian whose work has chiefly focused on the social history of 20th-century Germany. He is regarded by many as one of the world's foremost experts on Adolf Hitler and Nazi Germany, and is particularly noted for his biographies of Hitler.

Adolf Hitler was an Austrian-born German politician who was the dictator of Nazi Germany from 1933 until his suicide in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and then taking the title of Führer und Reichskanzler in 1934. During his dictatorship, he initiated the European theatre of World War II 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: the genocide of about six million Jews and millions of other victims.