Trench Crusade: The Eighth Hundred Years

It is 1914, and the war has never ended. Since the Knights Templar tore open a Gate of Hell beneath Jerusalem in 1099, the armies of the Faithful have fought eight centuries of grinding, holy trench warfare against the legions of the damned. Mud, wire, prayer, and cannon-fire define the front. Your warband is all that stands between the mortal world and the next infernal advance.