Mass Effect Universe Timeline
Table of Contents
Prehistoric Times (Unknown BCE - 1,000,000,000 BCE)
- The Leviathans dominate the galaxy, enthralling every new sapient race they encounter and protecting them in return for tribute. The Leviathans consider themselves the galaxy's first and only apex race. After observing that their subservient races create synthetic races who consistently and violently rebel, the Leviathans create an Intelligence to seek a way to permanently preserve organic life.
- The Intelligence creates 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 mandate.
- The Intelligence creates the mass relay network to increase the efficiency of the cycles, allowing galactic civilizations to develop faster and more consistently between harvests.
Pre-Prothean Times (1,000,000,000 BCE - 68,000 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.
- 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.
- 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.
- 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.
Pre-Council Times (68,000 BCE - 500 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 intelligences 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.
- 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.
- 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.
- 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.
- 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.
- The salarians discover the Citadel and open diplomatic relations with the asari.
Council Era - Formation (500 BCE - 1 CE)
500 BCE: Founding of the Citadel Council
- 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.
200 BCE to 1 CE
- 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.
Council Era - War and Rebellion (1 CE - 900 CE)
1 CE: The 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.
- 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.
- 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 to 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.
- Bilo Geerjay, a former salarian operative, becomes the first Council Spectre.
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.
- 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.
- 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.
Council Era - Expansion (900 CE - 2157 CE)
- The turians are granted a seat on the Citadel Council in recognition for their service in the Krogan Rebellions.
- Extensive and unchecked industrial expansion on the drell homeworld Rakhana begins taking a significant toll on the planet's environment.
- The first sightings of the Collectors are reported in the Terminus Systems. In Citadel space, the claims are dismissed as unsubstantiated rumors and tall tales.
- Samara's three daughters are diagnosed as Ardat-Yakshi. Rila and Falere accept exile, but Morinth flees. Samara takes the oaths of the asari justicars and pursues her errant daughter for the next 430 years.
- Aria T'Loak arrives on Omega, a space station in the Terminus Systems regarded as the region's nominal capital. Aria is hired by the station's warlord as an enforcer and quickly becomes one of his most trusted lieutenants.
1895 CE: The Geth War
- 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.
- 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.
- April 12: Yuri Gagarin aboard the Vostok 1 becomes the first human to travel in space. Humanity becomes a spacefaring race.
- July 20 - Apollo 11 lands on Luna. Neil Armstrong becomes the first human to walk on Luna, and the first human to walk on an astronomical object other than Earth.
- Aria T'Loak assumes control of Omega after defeating the space station's previous warlord in single combat. She mockingly bestows the title "Patriarch" on the broken krogan, and uses him as a reminder to her enemies of her power.
- 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 largescale 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.
- July 20: Armstrong Outpost at Shackleton Crater is formally founded as the first human settlement on Luna, on the 100th anniversary of the first lunar landing.
- Billionaire Victor Manswell, frustrated with the pace of official human space exploration, begins funding his own private spaceflight expedition.
- The Manswell Expedition successfully launches from Earth en route to the Alpha Centauri system with 300 colonists aboard in cryogenic stasis. Communications with the vessel are lost soon after.
- Liara T'Soni is born.
- The European Space Agency's Lowell City in Eos Chasma becomes the first permanent human settlement on Mars.
- 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.
- Steven Hackett is born.
- David Anderson is born. The Eldfell-Ashland Energy Corporation demonstrates helium-3 fuel extraction from the atmosphere of Saturn.
- Saren Arterius is born.
- Kahlee Sanders is born.
- Construction of Gagarin Station (Jump Zero) begins beyond the orbit of Pluto.
- Thane Krios is born.
- Trace amounts of element zero are discovered on Mars.
2148 CE: Humanity Discovers Mass Effect Physics
- Humanity discovers a small cache of highly advanced Prothean technology hidden deep beneath the surface of Mars on the south polar region of Promethei Planum. Building on the remnants of this long extinct race, humans quickly explore the science of mass effect fields, leading to the development of faster than light travel and beginning detailed exploration of the Sol system.
- Following information from the translated data cache on Mars, humans discover that Charon, Pluto's moon, is actually a massive piece of dormant Prothean technology, a mass relay, encased in ice. Once activated, Jon Grissom leads the first team of explorers through the relay, which instantaneously transports them to another relay in Arcturus, 36 light-years away. The explorers discover that the mass relays are part of a vast network, making travel across the galaxy possible.
- The Systems Alliance charter is signed by the eighteen largest nations on Earth. The Alliance soon becomes the military and exploratory spearhead of humanity.
- Miranda Lawson is born.
- The Systems Alliance begins the first surveys for colonization prospects outside the Sol System. One of these surveys discovers the planet Terra Nova.
- To defend its expanding territory, humanity begins constructing a massive military fleet and space station at Arcturus, the nexus of several key mass relays, even though they have yet to encounter another intelligent spacefaring race. An accident at Singapore International Spaceport exposes hundreds of humans to dust-form element zero. Roughly 30% of the children born in Singapore after element zero exposure suffer from cancerous growths. After his mother is exposed during the accident, Kaidan Alenko is born later that year with biotic potential.
- The Delta Pavonis Foundation, a major consortium based on Earth, begins settlement of humanity's first extra-solar colony world, the planet Demeter.
- Later that year, additional colonies are founded on Eden Prime and Terra Nova.
- Thane Krios is submitted for training as an assassin under the hanar.
- April 11: Shepard is born.
- There is a second publicized accident involving the exposure of humans to element zero.
- Saren Arterius is promoted to active service in the turian military at the age of 16.
- The Systems Alliance occupies completed portions of Arcturus Station, intended to become the Alliance's headquarters.
- Jeff "Joker" Moreau is born.
- Arcturus Station is formally inaugurated. A small number of human children exposed to element zero exhibit minor telekinetic abilities.
Council Era - Advent of Humanity (2157 CE - 2183 CE)
2157 CE: The First Contact War
- Pluto's orbit becomes circularized as a result of mass relay operations.
- Jacob Taylor is born.
- David Anderson graduates from Officer Candidate School with the rank of Second Lieutenant.
- Humanity makes violent first contact with another spacefaring race: the turians. The turians observe human explorers attempting to activate a dormant mass relay, a practice forbidden by galactic law after the Rachni Wars, and attack. Over the next three months a brief, but tense, conflict known by humans as the First Contact War and by turians as the Relay 314 Incident ensues.
- Admiral Jon Grissom travels to Arcturus Station to congratulate graduates of the Systems Alliance's N7 training program and meets David Anderson. Grissom announces that an unknown alien force has attacked an Alliance post at the colony of Shanxi.
- The First Contact War culminates in the turian siege and occupation of Shanxi, the first human world to fall to an alien race.
- Admiral Kastanie Drescher leads the Second Fleet in battle against Shanxi's occupiers one month later, catching the turians by surprise and evicting them from the planet. The turians prepare for a full-scale war against humanity, but this draws the attention of the Citadel Council.
- The Council intervenes before hostilities escalate further, revealing the existence of the greater galactic community to humanity and brokering a peace between them and the turians.
- While aiding the human resistance effort on turian-occupied Shanxi, mercenary Jack Harper becomes embroiled in a plot by turian general Desolas Arterius to use an ancient alien artifact, the Arca Monolith, to convert the turian race into an army of invincible "meta-turians". Harper convinces Desolas' brother Saren of the dangers of the Monolith, which is "devolving" the turians into mindless beings under the Monolith's control. To protect his people, Saren orders the destruction of the building holding the Monolith, Temple Palaven, with Desolas and the meta-turians inside.
- Later, having realized that humanity and the galaxy face dark times ahead, Harper founds the human-survivalist organization Cerberus, publishes its manifesto, and assumes the identity of the Illusive Man.
- An anonymous extranet manifesto is published following the end of the First Contact War. The manifesto calls for an army, a "Cerberus", to be established to defend humanity against inevitable alien attacks. Derided as "survivalist rhetoric written by an illusive man", the manifesto is quickly forgotten by the media.
- Humans learn the potential of biotics. An international effort to track element zero exposures begins. Roughly 10% of recorded exposed children show indications of biotic ability.
- April 14: Ashley Williams is born.
- Saren Arterius becomes the youngest turian to be inducted into the Spectres.
- The Systems Alliance purchases Gagarin Station for a fraction of its construction cost, and converts the facility into a biotic research and training facility.
- The Systems Alliance Parliament is formed.
- With the existence of human biotics firmly established, the Biotic Acclimation and Temperance Training (BAaT) program is set up on Gagarin Station to train potential candidates and develop biotic implants.
- The biotic drug red sand is first used.
- The Blue Suns mercenary group is founded by Zaeed Massani and Vido Santiago in the Skyllian Verge.
- Kasumi Goto is born.
- Amid concerns over gene therapy and genetic modifications being misused, the Systems Alliance Parliament passes the Sudham-Wolcott Genetic Heritage Act. It imposes sharp restrictions on controversial uses of genetic engineering, but provides government subsidies for beneficial applications.
- Tali'Zorah nar Rayya is born.
- Jack is born.
- Construction of Arcturus Station is completed.
- A survey team working for batarian entrepreneur Edan Had'dah discovers a mysterious artifact orbiting an unnamed planet near the Perseus Veil.
- The Alliance secretly begins illegal AI research at a base on Sidon with Dr. Shu Qian as project leader. Lt. Kahlee Sanders is assigned as a tech analyst.
- The first experimental L1 biotic implants are used in humans.
- A series of starship drive failures are orchestrated over populated areas on human colony worlds, causing widespread exposures to element zero. This results in a second generation of humans born with biotic potential.
- The Leviathan of Dis, a genetically-engineered living starship believed to be nearly a billion years old, is discovered by a batarian survey team on the planet Jartar. The Leviathan disappears under dubious circumstances after a batarian dreadnought passes through the Dis system.
- Ivor Johnstagg is sentenced to 21 years in prison for attempting to assassinate Venta Tox, the volus ambassador to the Citadel. Although Johnstagg claims to be acting on behalf of the radical human political party Eternal Earth, no connection is found and Johnstagg is diagnosed with paranoid schizophrenia. Backlash from the assassination attempt jeopardizes the Systems Alliance's bid for an embassy on the Citadel.
- Humanity continues to expand, founding more colonies and establishing trade alliances with many of the other species who recognize the authority of the Citadel Council. The Council makes official recognition of humanity's growing power and influence in the galactic community.
- Humanity is granted an embassy on the Citadel, the political and economic heart of the galaxy.
- Tensions grow between humans and batarians as they compete for territory in the Skyllian Verge.
- After an Alliance research station at Sidon is attacked, David Anderson searches for those responsible alongside Kahlee Sanders, and discovers an Alliance scientist, Dr. Shu Qian, was conducting illegal AI research to unlock the secrets behind a mysterious artifact discovered near the Perseus Veil. Eventually, Anderson is assigned to work with Saren Arterius to track down Dr. Qian and his batarian supporter, Edan Had'dah. However, Saren instead kills both Dr. Qian and Had'dah, blames Anderson for the mission's failure, and uses Dr. Qian's research to search for the artifact himself.
- Terrorists steal antimatter from the Alliance cruiser SSV Geneva. The sole figure arrested names his sponsor "Cerberus". This is the first such incident of sabotage connected to the Cerberus organization.
- After a disagreement between Vido Santiago and Zaeed Massani over hiring batarians into the Blue Suns, Vido betrays Zaeed and leaves him for dead. All records of Zaeed's involvement in the Blue Suns are erased.
- Jack is abducted by Cerberus agents on Eden Prime. They fake her death and take her to the Teltin Facility on Pragia as part of a project intended to improve biotic potential in humans.
- Commander Vyrnnus, a turian mercenary, is hired to oversee the training of human biotics at BAaT.
- L2 biotic implants are first developed and used in humans. Kaidan Alenko is among the first to receive the new implants.
- The magazine Fornax is launched.
- Kaidan Alenko accidentally kills Commander Vyrnnus after being provoked. The diplomatic fallout with the turians results in BAaT being shut down a year later.
- The human colony of Mindoir is attacked by batarian slavers. Many colonists are killed or captured.
- Another human colony, Yandoa, suffers catastrophic dust-form element zero exposure to its atmosphere when an Eldfell-Ashland Energy ship explodes in orbit. Many children suffer birth defects; thirty-seven biotic children are born, including Gillian Grayson.
- Biotic training for humans is outsourced to the military, selected R&D companies, and renamed divisions of the defunct Conatix Industries.
- L3 biotic implants are developed after L2 implants prove to be dangerous.
- The first A-61 Mantis Gunships are produced.
- In protest at the refusal of the Citadel Council to limit human expansion in the Skyllian Verge, the batarians close their embassy, withdraw into their home systems, and effectively become a rogue state.
- Cerberus assassinates Pope Clement XVI on Earth via rosary beads coated with toxic substances; his death is attributed to age and heart failure. His successor, Pope Leo XIV, espouses beliefs more in-line with Cerberus' ideals.
- April 11: Shepard enlists in the Alliance military.
- On Gagarin Station, "Eliza" becomes the first sapient AI created in the Systems Alliance.
- A fly-by over the world of Armeni discovers odd surface protrusions. Upon closer inspection, they are identified as elaborate crypts made by the zeioph, an extinct spacefaring race. Various human universities seek to perform excavation, but Council laws that hold burial sites as sacrosanct prevent this. An ongoing debate over the issue ensues.
- Terra Firma is involved in a Nashan Stellar Dynamics kickbacks scandal, forcing Inez Simmons, the current party leader, to resign. Charles Saracino becomes the new party leader after his opponent, Claude Menneau, is assassinated by Cerberus operatives while en route to Shanxi. Publicly, Menneau's disappearance is never explained.
- Kaidan Alenko enlists in the Alliance military.
- Ashley Williams enlists in the Alliance military.
- On a survey mission to 2175 Aeia, an important colonization prospect for the Systems Alliance, the MSV Hugo Gernsback disappears and is presumed destroyed.
- Cerberus covertly contacts Michael Moser Lang, a political dissident on Earth, and provides him with funding to purchase weapons. Cerberus continues to monitor him after contact ends. One year later, Lang assassinates United North American States president Enrique Aguilar and Chinese People's Federation premier Ying Xiong. The resulting political shuffle benefits Cerberus' shell companies and plans for the Systems Alliance Parliament.
- Batarian-funded pirates and criminals launch a surprise attack, later known as the Skyllian Blitz, on the human colony of Elysium. The assault is repulsed by the Alliance Navy and ground teams.
- The Jon Grissom Academy is commissioned over Elysium, and becomes home to the Alliance's new biotic training program, the Ascension Project.
- The Anhur Rebellions, a civil war waged over the practice of slavery, begin on the human and batarian colony world of Anhur and spread throughout the Amun system. Abolitionism supporters hire the Eclipse mercenary group to fight the batarian pro-slavery Na'hesit faction.
- Miners at the T-GES Mineral Works facility on Mahavid uncover a Leviathan artifact. The miners are enthralled by the Leviathans for the next ten years and are used to carry out numerous experiments.
- During a recon mission to find a missing colonial pioneer team on Akuze, a unit of fifty Alliance marines is wiped out by thresher maws.
- In retaliation for the Skyllian Blitz, the Alliance launches a major offensive against the moon of Torfan and destroys the criminal bases there, mostly populated by batarians. The threat against human colonies from batarian extremists is curtailed.
- The Alliance tracks several pirate FTL exit vectors over a period of six months using covert monitoring devices planted on Theshaca's moons, leading the Alliance Navy to eight major pirate anchorages. Since the "Theshaca Raids", no ships from the Terminus Systems have entered the Hong system.
- The Anhur Rebellions end with the abolitionist forces in power, and the reconstruction of Anhur commences.
- Admiral Kahoku of the Systems Alliance begins investigating suspected Cerberus activities.
- Humans and turians collaborate on an engineering project co-sponsored by the Citadel Council: an experimental frigate with a prototype stealth system, the SSV Normandy. David Anderson is given command of the ship, and Commander Shepard is assigned as executive officer.
2183 CE The Eden Prime War
- The human colony of Eden Prime is attacked by the geth, initiating a wider conflict between humans and geth known as the Eden Prime War. After exposing the involvement of rogue Spectre Saren Arterius in the attack, Commander Shepard and the crew of the SSV Normandy pursue Saren in his search for the Conduit, later revealed to be part of a larger plan orchestrated by the Reaper Sovereign to return its kind to the galaxy.