How Winston Churchill defeated Nazism despite his 'black dog'

Winston Churchill inspired his fellow Britons to resist the rise of the Nazis and led them to victory in World War Two. All this in the face of a complex childhood, a love for alcohol and a self-described long battle with the 'black dog' of depression. Andrew Roberts is the author of Churchill: Walking with Destiny, the most recent and highly-regarded biography of the man who was the twice-prime minister of Britain.