During the First Crusade, the armies of the Church captured the Holy City. Under the most holy of temples, the Knights Templar discovered secret vaults and, within them, an ancient demonic artefact. The Templars, blinded by greed and with weakness in their hearts, fell to their knees. They had found a new lord. Seeing the unholy wisdom of which the artefact spoke, they began trafficking with devils and committing all manner of unspeakable rites. This was the First Heresy. The armies of the Church retreated and Jerusalem became a depraved pit where Hell and our mortal plane now bled into one. For eight centuries the Church has waged its crusade to take back the Holy City. The landscape has been utterly devastated, criss-crossed with thousands of miles of mud, trenches and craters. The crusade is now waged with armies wielding terrifying weaponry, and both sides conjure up supernatural beings of such immense power they are nigh unstoppable. Even with such incalculable might, the armies are at a stalemate.

This is the Trench Crusade.

In this horrifying alternative timeline, the year is 1914. The Great War between the massive forces of the Church and Hell has reached it's most bloody and violent peak. After suffering over 800 years of apocalyptic warfare the planet is a crumbling, sad shell of what it once was. An endless fog forever envelops the battlelines in eerie silence before the thunder of war inevitably erupts. Mile after mile of Christian crosses, angel statues and churches acting as garrisons and pillboxes extend across the lands. The massive artillery barrages pockmark no man’s land, creating a hellscape on Earth between the Heretic and Faithful forces, vistas of deep mud and sludge, huge craters, twisted barbed wire, millions of shell casings and rotting corpses of both human and demon alike swarmed by clouds of vicious flies. Hands extend from the mud, drowned below in the deluge of rainwater and blood, the chaos of war. Titanic sized artillery exceeding 300 feet in size are deployed from the foundries of New Antioch and Hell's portals, up to almost 1666 millimetres in calibre! Absolutely decimating anything they hit on the enemy lines. Unique forms of gas are often used by artillery against the forces of the Church and Hell in order to attack trenches, a deadly green cloud that sweeps the lines, suffocating the unprepared.

The Faithful forces of the Church, known as the Principality of New Antioch, are the first and last line of defence against the hordes of Hell. Led by Duke Constantine XI they are nigh-unbeatable with incredibly tough defences, especially in their Fortress City of Levant. New Antioch's role in the defence of the Church is key, and so the fortress-city specializes in defensive tactics. Its gargantuan famed walls, with their seventy-seven mighty towers, have never been breached. This is partly due to the hundreds of Anchorite Shrines embedded within the walls, keeping a vigilant watch day and night.

Heavily inspired by the traditional uniforms of World War 1 mixed with the garb and habits of the Church, their forces often look like monks, priests, pastors and nuns wearing gas masks and pieces of knights armour on their limbs. Life on the frontline trenches is indescribably bad, sodden with rain and heavy fog, rotting food, horror and blasphemy. Prayers and scripture reading is an almost minutely occurrence among the troops.

A shroud of darkness blankets the world. Smoke and brimstone spews from the yawning gates of Inferno, enveloping the lands where people have abandoned God and openly wage war against His Creation. It is a grim reality that a full third of humanity has bent its knee before the idols of Hell. The main military force of Satan on Earth is the Heretic Legions, raised from amongst these citizens of the damned. Though the vast bulk of the Heretic Legions are made of mortal humans, Hell often sends their own nightmarish War Beasts made of captured and possessed creatures and dreaded Artillery Witches.

This is a war not just for survival but for humanity's soul.