House Taranis

House Taranis is a Knight House (a feudal Imperial household fielding armoured Knight suits) of the Adeptus Mechanicus, seated on Mars. It is remembered in Imperial record as the first Knight House ever raised, its lineage predating every other household by many centuries and loyal to the Imperium and the Machine God alike. Uniquely among the Knight Houses, Taranis never adopted the feudal hierarchy or the mind-altering conditioning built into the Thrones Mechanicum of its peers; the reasons for this omission, like much of the house’s earliest history, are recorded as lost to time, though later tradition holds that its founding Nobles were already bound in loyalty to the Mechanicum before such conditioning was devised.

Accounts differ on the exact era of the house’s founding, placing it variously in Mars’s Age of Technology or the subsequent Age of Strife, well before the unification of Terra. Tradition credits the warlord Cheops Taranis with uniting the largest Knight formations on the Red Planet under a single banner, a Writ of Vassalage to the Martian Mechanicum that later tradition holds was in time formally ratified by the Officio Militaris College of Arms. As Mars grew into the first and foremost of the Imperium’s forge worlds, House Taranis stood as its guardian, and the Standard Template Construct designs for Knight-pattern exo-armour later carried across the stars during the Great Crusade are held to derive from suits first developed for its Nobles.

By the opening of the Horus Heresy, House Taranis fielded some six hundred Knight suits, including rare Porphyrion, Atrapos, Magaera and Styrix patterns, making it one of the best-equipped households sworn to Mars. When the forge world’s Loyalist and Traitor factions turned on one another in the Schism of Mars, Taranis fought for the Loyalist cause at the Battle of Mars and was all but annihilated by the Dark Mechanicum; only the Nobles Raf Maven and Leopold Cronus are recorded as surviving, going into hiding for the remainder of the Horus Heresy’s civil war. Detachments of the house fought elsewhere during the same conflict, including the Defence of Ryza and the Siege of Inwit, the latter alongside engines of the Titan Legion (a Collegia Titanica engine-house fielding god-engines) Legio Ignatum.

In the war’s aftermath, Raf Maven rebuilt House Taranis from its few survivors and, in honour of his fallen kinsmen, added a sword bisecting the household’s cog-and-crest emblem, a mark it has borne since. Tradition holds that Taranis’s Knights repainted their suits from the dark blue and white worn during the Great Crusade to the red, black and silver they bear today, in recognition of their debt to the Loyalist forge worlds. In later millennia the house is recorded fighting in numerous Imperial campaigns, among them the Indomitus Crusade, the Charadon Campaign and the Pariah Crusade, maintaining its long-held standing as first among the Knight Houses sworn to Mars.