51952 BGS*
Humanity and the Protheans amongst many smaller races built vast stellar empires upon the ruins of the long dead lnusannon race. For thousands of years both powers held the dominant positions of power throughout the relay network.
A cold war fought with foot soldier races and proxys races was seen as the natural evolution of Human - Prothean relations and so with each new step in the conflict few in either government suspected any exterior influence to be the cause of the two super powers state of war.
This lack of suspicion ended with the fall of the Human colony of Tiber a militaristic planet which formed one of the core pillars to the defense of Humanity's space that was hosting the latest in a long line of unsuccessful peace talks.
the galactic order was truly shattered above Tiber when the Rachni were unleashed, an unknown foe that overwhelmed the local planetary defenses, the Human 3rd fleet and the Prothean ambassadors escorts. In the heart of the swarm lay a ship that dwarfed all others both Prothean and Human, a squid shaped vessel far different from conventional design. Sovereign has stepped out of the shadows to show himself and triggered the end of the cycle.
The loss of Tiber lead to confusion and eventual open war between both factions. This allows Sovereign the chance to move on the Citadel using his indoctrinated Rachni to call forth his brethren from dark space. The following decapitation of the Prothean empire throws the last vestiges of galaxy wide order to the wind. The cycle will continue and there is little that can be done to stop it.
50731BGS
Admiral Cole was a tired man, the last remaining Admiral of note left in the ever dwindling military. He has been leading the Human forces in what he knows is the end game in the near 1200 year Reaper war. Old political divisions long gone his "resistance fleet" contains both Prothean and Human ships. With the loss of the home worlds and all notably colonies they stand guard over Carthage a resource poor colony spared in the war so far. Once nothing more than a penal colony it now harbours the political and military vestiges of the former superpowers.
Cole knew that he was going to die as one by one the few remaining friendly contacts across the stars went quite, it was only a matter of time until the Reapers found his forces. The last hope for both Races and the reason that he fights on is the Repository.
The brain child of a faceless administrator from the Office of Naval Intelligence who concluded that there was no winning the current war of attrition. The Repository aims to beat the Reapers by expoliting the cycle, it's a ship 10km long 2km wide cylindrical in shape that holds the collective knowledge of the Human race and Prothean empire. Asides from the data banks it also holds the genetic information for 1 million refugees and an artificial intelligence specifically designed to aid in the reclamation of both species.
50723BGS
The Respository is launched from Carthage, it heads out into the void to the space between relays far away from any system ever scouted. It will spend 10,000 years in the void drifting through the stars on a long journey avoiding all potential contact until the core directive deems it safe to return to known space and build anew what was lost before.
After the lauch all knowledge of the project is purged under the order of Admrial Cole as to avoid the ship falling into Reaper hands. Three months later on the 21st of June in the old Earth calendar the Reapers flood through the in system relay. In a final act of defiance after the loss of most of the defending fleet and the Reapers have moved in for orbital bombardment Admiral Cole triggers the Ragnarok protocol. burried deep within the crust of Carthage several devices are triggered mass effect fields spread to cover the surface dramatically increasing the mass of the planet for a few short seconds. The resulting implosion of Carthage wipes out everything and destroys 400 Reaper capital ships.
His last words a mix of hope, pride and vengeance "Dulce et decorum est pro patria mori"
Hey guys so this an idea I had that I wanted to get down on paper. Not entirely sure if it will develop into a full length fic but there will be several more chapters after this short introduction up to the point of first contact. This is going to be pure Mass Effect despite the occasional Halo name drop obviously heavily AU.
*BGS =before galactic standard. 0GS is the foundation date of the Citadel in Mass Effect.