I've left this idea floating around in my mind for quite some time now and I think I finally have a decent sinopsis for such a chapter, but before starting to work on a fully develloped IA for this chapter I thought it "safer" to run my ideas through the DiY masters here at B&C. So, here are the initial ideas...
Eldaris Xenos Non Patieris Vivere.
Founding: 5th (I want them to be fairly ancient for their reputation as boarding actions experts to be established widely enough throughout the Imperium)
Homeworld: None, they are a fleet based chapter. Though they have in the latest millenia (since late M38) been more or less active only in the Northern regions of the Segmentum Ultima and more precisely the Atlarian Sector.
Organisation: They are a Codex chapter, following the teachings of the beloved Primarch to the letter. However, over the millenia since their creation, they have become specialized in space fighting and boarding actions.
History: In 539M38, the Warpstorm known as "The Wrath of Saint Lacrimae" [for more about this Warp Storm see here] reached the Chronian sub-sector and cut the normal shipping routes between the Mining Worlds of the Lewarde System and the Forge-World of Etueffont XC, forcing the vessels to choose a lesser evil and cross the Gulf of Pandora, a Warp anomaly, a zone of calm in the Empirean, devoid of any current.
The Navis Nobilite archives show that the Gulf had always been avoided because its crossing is impossible via the Empyrean and thus forced the vessels which wished to cross it to exit the Empyrean and attempt the trip on conventional propulsion alone for several weeks before reentering the Warp to finish their travel, hence mutiplying the risks inherent to any Warp translation and increasing the average travel time. But with the Storm blocking the other possible ways, crossing the Gulf became the only solution.
Almost immediately, the vessels attempting the crossing of the Gulf were attacked by Eldar pirats, who destroyed over 50% of the vessels, heavily impacting the production levels of the Forge-World. A Navy fleet was sent from Kar Duniash with the mission to put an end to the xenos threat in the Gulf but the fleet had only limited success, allowing only a fraction more of transport vessels to reach their destination while being slowly but surely reduced in numbers with each encounter with the fast Eldar ships, at such a rate of attrition, the fleet would not have survived very long.
It was at this point that the Venators, reknown throughout the Imperium for their anti-piratical actions, were called upon by the Lord of the Administratum [Anyone knows the actual ranks of this branch of the Imperial machine?] of the Atlarian Sector.
Upon their arrival, the chapter master immediately saw the grave mistake made by the Navy Commander in choosing to try to organize the shipping vessels into caravans and escorting them through the Gulf. He knew that such a powerful piratical fleet needed a base of operation and that only by finding it could the gulf be secured. He thus set a trap, sending a caravan of empty old vessels, most of them quickly patched together ships saved from the scrap yards, to cross the gulf and, when the Eldar pirats attacked, let them destroy the caravan without interfering, before simply following them at a distance...
The Astartes Fleet soon found itself in an uncharted zone of the Gulf, filled with dense black nebulae, and the chapter master knew that the Eldar base must be hidden there. He sent small ships to scout the area and one of them quickly found the source of the Eldar presence in the reagion. Within one of the denser Nebulae lay a small system, a small sun and a single planet, a Maiden World known as Harathandirell to the Xenos.
The first intention of the chapter Master was to call Exterminatus on the planet, but, having learned of the presence of such a world in the middle of the Gulf, a world which could serve as a waypoint for the vessels forced to cross the Gulf, and which could be fitted as a Navy base to increase the Imperial presence in this area of the Sector and bring it back fully under Imperial rule, the Sector and Navy command put pressure on the Astartes to capture the world instead...
The space marines half-heartedly complied. They first launched a massive attack against the Haven Class Spire in orbit around the planet, capturing it at a high cost, and then planned a land assault to completely rid the planet of any xenos presence. But this action was to prove much harder than expected... The Eldar of Craftworld Alaitoc lend their help to their Exodite and Piratical brethren and the chapter found itself stuck in a fight for the planet which was to last for 15 years, each faction winning and loosing ground in turn.
Finally, after 15 years seeing his men falling at the hands of the Xenos, the Chapter Master received a message from the High Lords of Terra: the might of his chapter was needed elsewhere and the planet was to be considered Perdita and submitted to Exterminatus... Enraged by the useless loss of so many of his brethren, the Chapter Master complied immediately, but swore that the Xenos would eventually pay for the death of so many fine warriors. [I hesitate here, I could make him bomb the planet before the Imperial Guard units participating in the land assault could have been withdrawn, but I'm not sure it's a good idea]
Ever since, the chapter has engaged the Eldar wherever they met them, often to the detriment of other objectives...
(Note the black left kneepad, in memory of the fallen brethren of the Battle for Harathandirell)
So, that's about all I have come up with so far... I'm waiting for your comments, criticisms and ideas...
(A huge thanks to Iron_Father, from several other Warhammer 40000 communities for the wonderful work he did on the Chapter's symbol.)
Edited by Nash Trickster, 31 March 2011 - 11:46 AM.