The Great War in colour: Incredible photographs of the French army during World War I, 1914-1918

These color photos document life in the French army during World War One, and the destruction of towns and villages caused by German shelling. The pictures were taken by Paul Castelnau and Fernand Cuville using the photochrom technique and brought home the horrific realities of war.

The Western Front saw action throughout the length of the war and it was there that the conflict was finally decided. Except for a brief foray by the French into the region of Alsace, a German possession in 1914, the remainder of the fighting was conducted on French and Belgian soil (Belgium was wholly occupied apart from an enclave situated between Ypres and the French border); indeed, no Allied soldier set foot on German soil except for those taken prisoners.

The militarized zone of the front, which separated the zone occupied by the Germans from the rest of France, stretched 700 kilometers from the shores of the North Sea to the Swiss border and varied in breadth from a few hundred meters to several dozen kilometers.

It was essentially a line of defensive works comprising trenches, barbed wire entanglements, blockhouses, and underground shelters.

Millions of soldiers saw service on the front, where the incessant shelling of both sides transformed the area into a landscape of craters and desolation, and several million of them perished there after enduring the cold, unhealthy, and parasite-ridden conditions of the trenches.