Actium

The Forge World of Actium is located on the far western fringe of the Galaxy, in SegmentumPacificus, and a vital lynchpin in the Imperium's effort to bring order to the frontier. Actium was first brought into compliance during the Great Crusade, but was lost sometime after the War of the Beast to be rediscovered near the latter half of the Macharian Crusade. Actium's prominence in its home sector as well as to a limited degree the wider Segmentum is due to its ability to produce Battle Titans like the Reaver- and Warlord-Classes and the overall extremely high quality of its goods.

Great Crusade and Horus Heresy
During the middle years of the Great Crusade Rogal Dorn's 3rd Expeditionary Fleet arrived in the Actium system, identifying the presence of a Forge World and sending emissaries to the Tech Priesthood requesting Actium's submission to Imperial rule. Whether out of fear of the consequences of refusal or a genuine desire to rejoin wider human civilization the Fabricator-General agreed and invited the Primarch to the surface to finalize the details. When the Imperial Fists' Primarch passed through the blanket of storms surrounding Actium's sole supercontinent and landed in the capital Forge City of Tempestus Mons he was greeted by the assembled armed forces of Actium, thousands of Skitarii arrayed for his viewing along an avenue leading to where the Fabricator-General stood. Behind the ruler of Actium stood an honor guard of Legio Fulminata's God-Engines. The intended message was blatantly clear; Actium would join the Imperium, but would do so on its own terms, to be backed up by force of arms.

But there would be no battle for Actium, at least not then, for an accord was reached and the great manufactorum complexes of Actium began to churn out war material for the Great Crusade. Not only manufactured goods left the planet however, maniples of Legio Fulminata would serve alongside many Expeditionary Fleets, include the 3rd. Also dispatched were macrolades from Actium's Skitarii Legion, Legio Cataegis.

Actium was spared the horrors of the Tech-virus that crippled loyalist forces on Mars] at the onset of the [[:w:C:warhammer 40k:Horus Heresy|Horus Heresy and so was in a position to strike back against the Traitors immediately both industrially and militarily. Fresh shipments of arms, armor, ammunition, vehicles, and other equipment flowed to the beleaguered loyalists, guarded by Legio Cataegis and Fulminata.

Great Scouring
For their decision to honor the pact they had made with the Emperor the Tech Priests of Actium drew the ire of the Word Bearers. Traitor marines assailed the Forge World when it was most vulnerable, with the majority of its armed forces elsewhere aiding in the Great Scouring. However salvation would come when the Imperial Sentinels chapter, of Rogal Dorn's genetic legacy, shattered the Word Bearers' fleet in the void and then travelled to the surface to help Actium's defenders finish off the traitors. In payment Actium provided the Sentinels with a wing of Xiphon Interceptors which had been kept in storage after production of the fighters was ceased.

War of the Beast
It is at some point during the chaos of the War of the Beast that Actium disappears from Imperial records for almost nine thousand years.

Macharian Crusade and Heresy
At the tail end of the fourth century of the 42nd millennium Lord Commander Solar Macharius's crusade reached Actium. As had happened so long ago the Forge World gladly rejoined the Imperium, receiving Macharius in the same manner they had Dorn. Resupply and replenishment of the Crusade's forces was Actium's foremost task, one they performed admirably.

After the death of Macharius and the fracturing of his conquests into petty empires Actium supplied the campaign to suppress the Macharian Heresy.