On This Day: The Battle of Verdun – the longest engagement in WWI - ends

DECEMBER 18, 1916: The Battle of Verdun – the longest engagement of the First World War – ended on this day in 1916 after ten months of fighting and 976,000 casualties.

The Germans, who had aimed to “bleed the French white”, were ultimately defeated after the British launched an even bloodier offensive at the Somme.

For France, Verdun symbolised the slaughter of the war more than any other battle since three quarters of their 8.6million soldiers fought there at some point.

No engagement has ever sucked in so many men from one nation and this haunting collective experience would later lead to the French collapse in World War II.

This horror is outlined in silent British Pathé footage showing gruesome scenes of trenches full of bodies and thousands of others continuing the fight.

The battle began on February 21, 1916 after German General Erich von Falkenhayn ordered his troops to attack the fortress city of Verdun, on the Meuse River in France.

He convinced the Kaiser that, amid the trench warfare deadlock along the 600-mile Western Front, a catastrophic French loss at a single point would persuade Britain – their more feared adversary - to stop helping their ally and allow Germany to win.

He chose to strike Verdun, partly because of its symbolism as the last French stronghold to fall during the 1870 Franco-Prussian War.

Falkenhayn, who had been Chief of the German General Staff since September 1914, believed the French “would be compelled to throw in every man they have”.

Also, it was possible to attack the city from three sides, which made it a good strategic target in order to draw France’s forces into a costly counter-attack.

The Germans rapidly captured Fort Douaumont, the highest of fortresses in the hills above the city, and began bombarding Verdun below.

And, as Falkenhayn predicted, France’s General Henri Petain, who 25 years later signed the WWII Armistice with Germany, rushed in as many troops as he could.

Within days 20 divisions – around 330,000 Frenchmen – had arrived to fight on a point of national pride that quickly become a bloody stalemate.

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By the end of the battle, France was maintaining a constant force of 85 divisions - 1.14million troops -  although soldiers were regularly rotated in and out of the conflict.

They were outnumbered by the Germans, who numbered 1.25million men in 50 larger divisions.

In the end, the death toll was about equal – 156,000 Frenchmen and 143,000 Germans were killed. However, France suffered 100,000 more casualties - including soldiers missing or wounded - in total.

As well as the horrific number of casualties, Verdun saw the first uses of newly-invented German flamethrowers and phosgene poison gas.

The latter weapon was ten times more lethal than the chlorine gas they previously used.

But despite the Germans’ material advantages, the French will to regain the Côtes de Meuse hills never faltered.

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By July – when the British were persuaded to attack at the Somme and the Russians launched a new offensive in the East - German resources were stretched thin

Kaiser Wilhelm II, Queen Victoria’s grandson, was so frustrated that he removed Falkenhayn and sent him to command the 9th Army in Transylvania.

Paul von Hindenburg, who had warned against Verdun, took his place.

Petain was also replaced in April by Robert Nivelle, who helped France gradually claw back most of its lost territory by December.

On December 18 – after 11,000 Germans were taken prisoner in three days -  Hindenburg ordered an end to the attack.

The battle left France deeply scarred – with politicians who had fought at Verdun later advocating appeasement of the Nazi and arguing against rearmament.

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When Germany invaded again in May 1940, France were woefully prepared and vainly hoped their Maginot Line fortresses would be enough to repel the attack.

The country fell in six weeks and Petain, who had been hailed as the Hero of Verdun, was called on to lead the Nazi puppet state of Vichy France.

The will of resistance that had been so evident at Verdun perished in the aftermath and France became the only occupied country to sign an armistice with Germany.