A/N Hello all, first story! I hope this goes well, this first chapter is going to establish a timeline for events, Crossover for Halo, Mass Effect, and a little Command and Conquer. Please if you see grammatical errors or have constructive criticism on my story. Note this is a work of fiction and I do not condone many of the actions that may be present in this story. I do not own Mass Effect, Halo, Command and Conquer or any other universes that may be present in this story, please enjoy.
Timeline (Note the Halo human timeline starts before the Mass effect human thus making the date differences make sense, as well as this story takes place after Mass Effect 2 and Halo 4, Halo 5 technology will be seen here but the storyline doesnt happen as well as somethings are different as well I will not be editing the Human timeline histories this is the overall history of the Galaxy Exluding Humanity)
Unknown BCE -1,000,000,000 BCE
Precursors appear in the Milky Way Galaxy and start to seed life before moving on to the Andromeda Galaxy. During this time of life in the Milky Way the Leviathans evolve and soon span the galaxy while uplifting other sentient species and assisting them. It is during this time that they see the cycle of machine intelligence revolting against their creators and thus to seek a way to permanently preserve organic life they create The Intelligence. The Intelligence constructs an army of "pawns" to gather genetic information throughout the galaxy. The Intelligence betrays the Leviathans, using its pawns to slaughter them for their genetic material to create Harbinger, the first Reaper. Thus begins the cyclical harvest of the galaxy's intelligent organic life by the Reapers, part of a vast experiment conducted by the Intelligence to fulfill its Intelligence builds the mass relay network to increase the efficiency of the cycles, allowing galactic civilizations to develop faster and more consistently between harvests.
1,000,000,000 BCE
The Leviathan of Dis, a Reaper, is killed by the Leviathans. Its corpse comes to rest on the planet Jartar and remains undisturbed for nearly one billion years.
37,000,000 BCE
An unknown spacefaring race fires a mass accelerator round at a Reaper near the planet Mnemosyne. The round penetrates the Reaper, disabling it, and continues moving through space, eventually striking the planet Klendagon and creating the geological feature there known as the Great Rift Valley.
298,000 BCE
The ancient arthenn race flourish in the Zelene system, living on the planet Helyme until being destroyed in an unknown event that wiped out all complex life on the planet. They also maintained a presence on other planets in the system including Epho, which bears the scars of an ancient orbital bombardment, and Gaelon, which may have been mined for helium-3.
145,000 BCE
Ancient spacefaring races called the thoi'han and inusannon fight over the planet Eingana, littering the planet with the debris of hundreds of starships. Refined element zero scattered by broken drive cores contaminates the environment, causing many native species to go extinct and those that survive to show a tendency to develop biotic powers.
130,000 BCE
The Precursors return and see the cycle of extinction created by the intelligence and attempt to break the cycle by shutting down the mass relay network and decide to create the Mantle of Responsibility and two species evolve that have the potential to take control of the Mantle after they depart from this Galaxy to continue their journey, Forerunners and Humanity.
120,000 BCE
The Precursors decide that the Mantle of Responsibility shall go to Humanity. The Forerunners feel betrayed at this being the more advanced civilization and decide to attack the Precursors and destroy most of them similar to the Intelligence attacking the Leviathans. In response many Precursors leave while some grind themselves to a dust to be resurrected when the Precursors return.
110,000 BCE
Humanity encounters the Flood a parasitic organism that uses raw biomass to create more ways to spread. Flood forms found on Forerunner outer colonies and Humanity decides to destroy the surface of the planets before the Flood could spread further and leave the planet but in their haste they were unable to tell the Forerunners of this threat and thus the Forerunners attacked Humanity who was now weakened by the Flood. The war lasted centuries before Humanity lost and was de-evolved but not before destroying all data on the Flood and their Flood Cure.
103,000 BCE
The Flood is once more encountered on a Forerunner world and the research team sent to investigate disappears and thus a military team is sent in to determine what has happened. The team finds the Flood and what remained of the research team and send a warning to the Forerunner council about what is coming. The Forerunner council then realizez that humanity was telling the truth and now see the errors of their ways. This is when the Forerunner-Flood war begins and thus the Forerunner Empire was close to being destroyed.
100,050 BCE
The Forerunner council approves the creating of the Halo arrays as their final play to destroy the Flood. They task the Librarian with cataloging every sentient race in the Milky Way to reseed them across the Galaxy after the Halo arrays fire as well as setting Humanity as the Reclaimers of their technology by having Human DNA being able to easily use Forerunner technology.
100,000 BCE
The Halo Array fires destroying all Sentient life thus starving the Flood and was the final step in the fall of the Forerunners. Keyships from the Ark are sent out to the homeworlds of the species cataloged to reseed the Galaxy with Humanity being place on Earth. The Forerunner Monitor Stoic Reclamation decided to use a Keyship to destroy all of the Mass Relays in the Orion Arm of the Galaxy to protect humanity and even creates a second Sol system as a back-up plan to make sure Humanity achieves the mantle. Soon after the reseeding of the Galaxy the Reapers returned to the Milky Way reactive the Mass Relays and thus the Cycle is renewed.
68,000 BCE
The Protheans achieve spaceflight and discover mass effect technology from the ruins of the extinct inusannon. They go on to establish a galaxy-wide civilization linked by the mass relay network with the Citadel as their capital.
At some point, the Protheans encounter a hostile race of machine intelligence's that endanger their existence. To combat this threat, the Protheans aggressively assimilate many other spacefaring organic races into their empire. The Prothean Empire is able to fend off the machines in a conflict known as the "Metacon War".
48,000 BCE: Fall of the Protheans
The Prothean Empire collapses with the arrival of the Reapers through the Citadel. Although the Protheans had learned of the Reapers' existence from studying the ruins of previous civilizations and had begun to prepare, they were nonetheless caught off-guard. Over the next several centuries, the Protheans fight the Reapers system by system, world by world, and city by city. In the end, it is not enough. The Reapers methodically wipe out the remaining Protheans, as well as other contemporary races, and depart the galaxy to await the next cycle.
13,000 BCE
The Turians of Palaven begin to develop civilization around this time.
6,000 BCE
Seeking to escape the imminent explosion of their sun, an alien race constructs an AI-managed starship equipped with supercomputers containing a virtual world, into which some one billion of the aliens transfer their consciousnesses. The starship begins a journey throughout the galaxy which lasts for the next 8,000 years.
2,200 Covenant Calender
The San'Shyuum Civil War begins between the Stoics who believe that Forerunner Artificats should be reveared and not tampered with and the reformists who believe they should use the technology of their Gods to further their civilization.
2,100 Covenant Calendar
The century-long San'Shyuum Civil War came to an end as one thousand Reformists entered the Forerunner Dreadnought and fled the San'Shyuum homeworld.
1900 BCE
Tuchanka, the krogan homeworld, enters the nuclear age. In a global conflict, weapons of mass destruction are released, triggering a nuclear winter. In the resulting devastation, krogan society devolves into a collection of warring clans.
1800 BCE
A supernova propels the Mu Relay, the only point of access to the remote Pangaea Expanse, out of position. Concealed somewhere in the dense nebula formed by the supernova, the relay's position is effectively lost for centuries. Later, the rachni rediscover the relay.
938 Covenant Calendar
The San'Shyuum first encountered the Sangheili on Sanghelios who, like the Stoics, believed that Forerunner relics are to be worshipped, not modified. This ideological difference resulted in the Sangheili-San'Shyuum war, in which the Sangheili had a distinct advantage in infantry combat due to superior numbers and troop quality. However, in space combat the San'Shyuum had a great advantage because of their Dreadnought.
876 Covenant Calendar
After decades of struggle between the Sangheili and San'Shyuum in the Sangheili-San'Shyuum war, the Sangheili finally accepted that they must adapt and study their Forerunner relics or face defeat at the hands of the San'Shyuum. The Sangheili warrior priests reluctantly began using their relics to improve their warships, arms and armor.
852 Covenant Calendar
The Sangheili and San'Shyuum ended their war, merging to form the Covenant. The Council of Concordance ratified the Writ of Union, clearly defining the roles of the San'Shyuum and the Sangheili.
784 Covenant Calendar
During one of the first ages of Conversion Covenant forces discovered the planet Te and with it the Lekgolo. They discovered that many of the Lekgolo worm colonies had literally devoured Forerunner artifacts and installations, while others ate everything except Forerunner installations. The Lekgolo initially proved difficult to defeat because of their ability to combine into the powerful Mgalekgolo, however due in part to their superior spaceship technology the Covenant were able to ally with and tame the useful Lekgolo, and exterminate the relic-destroying colonies in what came to be known as the Taming of the Lekgolo. The compliant Lekgolo were incorporated into the Writ of Union in 784 BCE.
648 Covenant Calendar
TheSan'Shyuum homeworld was destroyed by a natural stellar collapse and the Forerunner dreadnought was made into the centerpiece of the new space station that would serve as the Covenant's capital, High Charity.
580 BCE
After developing faster-than-light spacefaring capabilities based upon Prothean technology, the asari begin to explore the mass relay network, and eventually discover the huge Citadel space station at a hub of many mass relays.
520 BCE
The salarians discover the Citadel and open diplomatic relations with the asari.
500 BCE- 1 CE
The Citadel Council is formed. The asari and salarians together colonize the Citadel and establish it as a center of the galactic community, led by the Council. This year is also known as 0 GS, the beginning of the Galactic Standard (GS) timeline.
As a gesture of openness with their new asari allies, the Salarian Union opens the records of the League of One. Under threat, the League responds by assassinating every member of the Union's inner cabinet; Special Tasks Group operatives then hunt down and eliminate the League.
First contact is made with the volus. Eventually, the Citadel Council commissions the volus to draw up the Unified Banking Act, which establishes a standard galactic currency known as the credit and links all galactic economies.
The turian Unification War occurs. The increasingly isolated and xenophobic colonies on the frontiers of turian space go to war with each other. After years of fighting, the Turian Hierarchy sweeps in and pacifies the remaining factions. Animosity between turian colonies continues for decades.
The Council grants the volus the honor of being the first non-Council species with an embassy at the Citadel, rather than a Council seat.
First contact is made with the batarians. They are granted an embassy a century later.
The asari discover the elcor home system and help the elcor locate and activate their nearest mass relay. "Within one elcor lifetime" they establish a regular trade route to the Citadel and are granted an embassy.
First contact is made with the hanar and the quarians. Both races are later granted embassies.
1 CE Rachni Wars
The rachni, a species of highly intelligent hive-minded insects, are discovered when a Citadel expedition opens a dormant mass relay leading to their star systems. The rachni prove to be hostile and begin a war with the rest of the galaxy. Negotiation with the rachni queens is impossible because they cannot be contacted in their underground nests on the toxic rachni worlds.
80 CE
The Rachni Wars continue. The salarians make first contact with and uplift the primitive krogan, manipulating them into acting as soldiers for the Citadel Council. The krogan prove able to survive the harsh environments of the rachni worlds and pursue the rachni into their nests, systematically eradicating queens and eggs.
300 CE
The rachni are declared extinct. In gratitude for their aid during the Rachni Wars, the Council rewards the krogan a new homeworld. Free of the harsh environment of Tuchanka, the krogan population explodes.
300 - 700 CE
The krogan begin to expand exponentially, colonizing many new worlds. Growing concerns about their expansion lead to the founding of the Special Tactics and Reconnaissance branch of the Citadel.
693 CE
Beelo Gurji, a salarian operative, is appointed the first Spectre by the Citadel Council.
700 CE: The Krogan Rebellions
Krogan warlords leverage veterans of the Rachni Wars to annex territory from other races in Citadel space. Eventually the Council demands withdrawal from the asari colony of Lusia, but the krogan refuse. A preemptive strike is made on krogan infrastructures by the Spectres. The Krogan Rebellions begin.
The Citadel Council makes first contact with the turians around this time and persuades them to aid in the war. After the krogan respond to the initial turian offensive by devastating turian colonies with weapons of mass destruction, the turians vow to stop the krogan from ever becoming a threat again.
Sometime after the turians join the galactic community, the volus are accepted as a client race of the Turian Hierarchy.
710 CE
Realizing that the krogan will never give in as long as they can replenish their fighters, the turians unleash a salarian-engineered bio-weapon known as the genophage on the krogan. The krogan population starts its decline.
800 CE
The Krogan Rebellions end, though scattered krogan insurgent actions continue for decades. The turians fill the military and peacekeeping niche left by the decimated krogan.
The Citadel Conventions are drawn up in the wake of the conflict.
900 CE
The turians are granted a seat on the Citadel Council in recognition for their service in the Krogan Rebellions.
1112 Covenant Calender
The Yanme'e; a tier 4 civilization, were incorporated into the Covenant as a slave race.
1342 Covenant Calender
The Covenant discovered the Kig-Yar. Although the Kig-yar initially attempted to resist absorption into the alliance they quickly recognized that they were facing a superior force and submitted, taking on the role of explorers and traders (and often thieves and smugglers). The Kig-yar were also motivated by the potential trade and wealth the Covenant could provide.
1400 CE
Extensive and unchecked industrial expansion on the drell homeworld Rakhana begins taking a significant toll on the planet's environment.
1895 CE
The geth, machines created by the quarians as a source of cheap labor, become self-aware. Fearing a geth uprising, the quarians begin dismantling them. The geth revolt against their quarian masters. In the resulting conflict-known to the geth as the Morning War-the geth systematically drive the quarians from their own worlds. The surviving quarians are reduced to living as spacefaring nomads aboard the Migrant Fleet. Contrary to expectations, the geth do not venture outside the former quarian systems into wider Citadel space, instead isolating themselves from the rest of the galaxy behind the Perseus Veil. As punishment for creating the geth, the Citadel Council closes the quarian embassy on the Citadel.
1921 CE
The geth begin construction of a mega-structure designed to house and simultaneously run every geth program in existence. Completion of the mega-structure, which would allow the geth to maximize their collective processing capacity, is the long-term goal of geth civilization.
2000 CE
The drell make first contact with the hanar around this time. With their homeworld Rakhana severely depleted and no spaceflight capability, the drell were poised for a massive population crash by 2025 CE. Agreeing to help, the hanar mount a large-scale rescue operation and evacuate approximately 375,000 drell to their own homeworld, Kahje, over the following decade. The remaining 11 billion drell on Rakhana gradually perish, warring over the last reserves of food and water.
2125 CE
The yahg, an intelligent pre-spaceflight race, are discovered on the planet Parnack. Ambassadors representing the Citadel Council arrive on the planet and attempt to open diplomatic contact. After the ambassadors are killed by the predatory yahg, the Council ceases all contact with the yahg and declares Parnack off-limits.
Not long after the yahg are discovered, one yahg is captured for the Shadow Broker to study. With the Broker's assistance, the yahg rapidly ascends within the Broker's organization as "Operative Kechlu". Eventually, the Broker becomes wary of "Operative Kechlu" and attempts to have him terminated, but the order is sent too late. The yahg assumes the mantle of the Shadow Broker and directs the organization for the next sixty years.
2142 Covenant Calender
the Covenant discover the Unggoy homeworld, Balaho. The Unggoy surrender almost immediately in the imposing presence of the Sangheili and are incorporated into the Covenant.
2462 Covenant Calender
The Unggoy Rebellion occurs. After much conflict in the Covenant, an Arbiter is sent in to end the rebellion. It's conclusion marks the beginning of the 23rd Age of Doubt and the ascension of the High Prophets of Tolerance and Restraint and the High Prophetess of Obligation.
2492 Covenant Calender
The Covenant stumbles upon Doisac, the Jiralhanae homeworld. The Jiralhanae were just beginning to recover after warring themselves back into a pre-industrial state, and were quickly forced into submission by the Covenant's superior forces, making them the final species absorbed into the alliance.
2525 Covenant Calender
The Ninth Age of Reclamation begins with the ascension of the High Prophets of Truth, Mercy and Regret. They declare that the Human race destroyed a vast Forerunner reliquary and are therefore to be exterminated, starting the Human-Covenant war. Thus the 30 year long Genocidal war and the start of an arms race begins.
2552 Covenant Calendar (Aka where all the Halo Games take place except for Wars, 4, and 5)
The penultimate year in the Human-Covenant war, during which the humans of the United Nations Space Command nearly saw utter defeat and extinction.
The Covenant were at the peak of their power and reach in 2552, with major assaults on the Human Inner colonies and an invasion followed by a prolonged engagement on their home planet, Earth.
During the battle at Installation 04, the ominous Flood were released for the first time in over a hundred thousand years.
Over two months later, Installation 05 was discovered, and the flood was released once more.
The war finally drew to a close at Installation 00, known more commonly as the "Ark", with the Humans and Sangheili attempting to assassinate the Prophet of Truth, before he could activate the remaining Halo Installations. The alliance was successful in their mission against the Covenant.
With the help of the Sangheili, the UNSC eventually won the Human-Covenant war.
2563 Covenant Calendar
The Covenant Remnant is finally defeated and peace settles throughout the Orion Ar,
2570 Covenant Calendar
With Covenant Remnant destroyed the former Covenant races decide to unite under one banner calling themselves as the Conclave of Indepednant Species (CIS) and decide to have an overal council to govern their territory.
2571 Covenant Calendar
The CIS form an official alliance with the UNCS trading many technologies between the two powers.
2572 Covenant Calendar 2185 CE
The UNCS Research and Exploration Vessel Light of Sol discovers a strange artifact resembling a giant tuning fork with giant rings inside it, believing they discovered a new Forerunner artifact they get ready to contact HighCom and begin studying the device.