It was broadly true that all European royalty were cousins; even the Habsburgs of Austria, most imperious of sovereigns, occasionally mingled their b… - John Keegan

It is one of the many graveyards which are the Great War’s chief heritage. The chronicle of its battles provides the dreariest literature in military history; no brave trumpets sound in memory for the drab millions who plodded to death on the featureless planes of Picardy and Poland; no litanies are sung for the leaders who coaxed them to slaughter. The legacy of the war’s political outcome scarcely bears contemplation: Europe ruined as a centre of world civilisation, Christian kingdoms transformed through defeat into godless tyrannies, Bolshevik or Nazi, the superficial difference between their ideologies counting not at all in their cruelty to common and decent folk. All that was worst in the century which the First World War had opened, the deliberate starvation of peasant enemies of the people by provinces, the extermination of racial outcasts, the persecution of ideology’s intellectual and cultural hate-objects, the massacre of ethnic minorities, the extinction of small national sovereignties, the destruction of parliaments and the elevation of commissars, gauleiters and warlords to power over voiceless millions, had its origins in the chaos it left behind. Of that, at the end of the century, little thankfully is left. Europe is once again, as it was in 1900, prosperous, peaceful and a power for good in the world.

The Somme marked the end of an age of vital optimism in British life that has never been recovered.

But then the First World War is a mystery. Its origins are mysterious. So is its course. Why did a prosperous continent, at the height of its success as a source and agent of global wealth and power and at one of the peaks of its intellectual and cultural achievement, choose to risk all it had won for itself and all it offered to the world in the lottery of a vicious and local internecine conflict? Why, when the hope of bringing the conflict to a quick and decisive conclusion was everywhere dashed to the ground within months of its outbreak, did the combatants decide nevertheless to persist in their military effort, to mobilise for total war and eventually to commit the totality of their young manhood to mutual and existentially pointless slaughter?