It is extraordinary that nobody has written a narrative history of Italy's Great War in English before. For this was not a minor sideshow in the First World War: Italy entered it more or less gratuitously, without the imperatives of survival that animated the other combatants, and was duly sneered at in London and Paris for being both venally calculating and lacking in military fervour. But once it got stuck into the vertiginous task of trying to dislodge the Austro-Hungarian empire from its strongholds high in the Alps, its soldiers began learning inch by inch the same lessons about barbed wire, trenches, grenades, poison gas, cretinous leadership and jingo journalists as were being learned hundreds of miles to the north in Flanders.