As the horrors raged in the trenches, and young men died in squalor by their thousands, back home in Britain a new national crisis had taken hold — one as unexpected as it was disturbing.

Thus it was that the Bishop of Birmingham, Russell Wakefield, rose to his feet at a specially convened summit at London’s Sunderland House to discuss what might be done to tackle this emergency.

It was December 1916. The serial adulterer Lloyd George was about to become Prime Minister. And the nature of the crisis? No less than a wide-scale collapse in public morality. Or as the prelate put it in his opening address, the deplorable way in which ‘every kind of looseness of life, almost, was encouraged by the war conditions’.

Few of the assembled throng needed reminding how this had manifested itself. Binge drinking, drug-taking and no-strings sex had become an undeniable feature of national life, not just among the upper classes, but even among the working men and women toiling on the Home Front and the soldiers back on leave.

A century after it began, nothing could be more at odds with our lasting impression of the Great War. To most it conjures up imagery of mud, rats, poison gas and rotting corpses, all of which loom so large in the poetry of Owen, Sassoon and Graves.

We often forget that, back home, Britons lived in fear not only of the growing death toll abroad but — since the ‘first blitz’ in January 1915 — also of Zeppelin air-raid attacks...