No contest this year. It is Max Hastings's All Hell Let Loose: the World at War, 1939-45 (HarperPress, £30) by miles, a great and dramatic book about the second-greatest and most dramatic event of the 20th century - the first being the First World War, of which the Second was the long-drawn-out continuation. Hastings weaves the high politics, the military strategies and the lives of nations, soldiers and civilians into a breathtaking tapestry. It is as if the whole of his previous life, as a war correspondent, journalist and historian, was a preparation for this hour. Which is what Winston Churchill, the hero of the book in so far as heroism features in this sorry and blood-soaked tale, said on assuming the premiership in May 1940.