Traditional name for the belligerent groups allied against the Imperium during the First and Second Frontier Wars . Commonly applied to any alliance of powers threatening the Spinward Marches and Imperial territories spinward of the Great Rift.
The original Outworld Coalition was formed in the early 500s at the instigation of the Zhodani Consulate. Vargr allegiances vacillated, but memories of the Imperial campaigns against certain Vargr states in Corridor swayed some into membership. Zhdant ( Gavel / Zhdant 2719), as the major partner, contributed military aid and assistance (such as technicians and advisors). While some Vargr governments contributed personnel and naval units, others remained neutral or sided with the Imperium.
The initial history of the Coalition was one of continuing struggle for organisation, as the Zhodani were continually occupied in establishing Vargr governments, and then maintaining them in power. The intent was for the Vargr to raid the coreward edge of the Spinward Marches, especially Regina and Aramis subsectors, while the major thrust from the Consulate took Cronor and Jewell subsectors. The Vargr portions of the offensive failed dismally. Furthermore, the failure resulted in a collapse of the Coalition.
The internal Imperial upheavals (the Civil War) which followed the First Frontier War (it was just known as the Frontier War then) exposed a continuing weakness in the Imperium, and the Outworld Coalition reformed after a hiatus of five years. At the appropriate moment, the reformed Coalition again attacked the Marches, this time taking portions of Jewell subsector. Although the Vargr again failed to take any territory, their performance was considerably improved.
Traditionally, frontier wars in the Spinward Marches have involved coalitions of Zhodani and certain Vargr states. The Sword Worlds have also joined the coalition at times.