Horus Lupercal, Warmaster of the Emperor's armies, has turned upon his gene-father and sent the Imperium spiralling into bloody civil war. Half of the great Space Marine Legions have sided with the traitorous Warmaster, and countless cohorts of the Solar Auxilia, Knight Households, and Titan Legions march at his side. Now brother fights brother as the Imperium's vast armies tear one another apart in a cataclysm of fire and blood. An age of darkness descends, the likes of which have never been witnessed before.
Warlord Battle Titans bestride the battlefields of the Horus Heresy, their thunderous tread heralding destruction. A mainstay of the Collegia Titanica, these Titans are among the largest war machines ever devised by the Mechanicum, and mount a vast arsenal of weapons – Arioch-pattern power claws shred enemy Titans in melee, while plasma annihilators offer intense mid-range firepower.
The Reaver Titan is one of the most ubiquitous and destructive classes of Battle Titan, a gargantuan war machine that forms the heart of the Titan Legions, holding the line or leading the charge as their Princeps demand. Whether unleashing awesome thermal blasts from a melta or volcano cannon, spitting beams of death from a turbo-laser destructor, or closing in to shred heavy armour with a roaring chainfist, the Reaver leaves enemies with one choice: flee or die.
The Knight Questoris is the most common suit of Knight Armour extant in the Imperium during the Age of Darkness, serving as the mainstay of Household forces and configured with a myriad of different armaments. Questoris Knights are frequently ﬁelded in Lances, consisting of multiple noble Scions operating in concert.
The Kratos Heavy Assault Tank is based on an Ancient Terran pattern, first fielded during the Unification of Old Earth. Redesigned after the Emperor's treaty with the Lords of Mars to serve as the spearhead of the Great Crusade, it excels as a line-breaker and foe hammer. Their steady, inexorable advance provides an indomitable core to any assault by the Legiones Astartes, enforced by a barrage of overwhelming firepower.
The Legiones Astartes employ their superhuman infantry to deadly effect. Clad in durable power-armour, armed with explosive boltguns and an array of heavier weapons, these Legionaries flow through debris-choked cities like water, bringing firepower to bear from unexpected quarters and charging in to strike where the enemy is most vulnerable. With the Legions split between the Loyalist Primarchs and the Warmaster's Traitors, the galaxy's most potent fighting forces now display their might against their own brothers for the first time.
The Rhino is the most widely used armoured personnel carrier in the Imperium. Based upon ancient STC technology, the fundamental design is robust, reliable, and easy to maintain, with an adaptive power plant that can run off a wide variety of fuels. Within the Space Marine Legions, the Deimos pattern was the most widespread, serving as the basic armoured transport available to the Legiones Astartes and the foundation on which a number of other war machines were based.
The Baneblade is a super-heavy tank outﬁtted with a bewildering array of weapons, even for a vehicle of its prodigious size. Each Baneblade serves as a mobile bastion, as well as a symbol of pride to those who march alongside it. The Baneblade hull also serves as the basis for a number of more specialised variants employed by the Solar Auxilia – including the Hellhammer, which exchanges the standard Baneblade battlecannon with a Hellhammer cannon that sacriﬁces range for increased destructive capabilities.
The Solar Auxilia are the elite corps of the Imperial Army, recruited from all across the galaxy. The soldiers of the Solar Auxilia are equipped with the weapons and gear to persecute war in some of the harshest environments imaginable. Though outmatched individually by the mighty Space Marines, these troops are far greater in number and prepared to throw down their lives for the cause – whether sworn to the Golden Throne of Terra, or the ambition of the Imperium's rebellious Warmaster.
The Thunderhawk Gunship fulfils a number of roles within the Legiones Astartes, but primarily acts as a drop ship, soaring through both atmosphere and void space to deliver its deadly cargo of Space Marines. It is also a formidable weapons platform in its own right, however, equipped to scour landing zones and engage enemy aircraft
Even in the Age of Darkness, the monumental architecture of the fledgling Imperium tends towards impressive edifices, a combination of baroque and gothic elements mixed with militaristic structures designed to stand in even the harshest environments.