
This year is also known as 0 GS, the beginning of the Galactic Standard (GS) timeline.

The asari and salarians together colonize the Citadel and establish it as a center of the galactic community, led by the Council. 1600 BCE In the Andromeda galaxy, the angara are created and seeded across multiple worlds in the Heleus Cluster by the Jardaan.ĥ80 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.ĥ20 BCE The salarians discover the Citadel and open diplomatic relations with the asari. Later, the rachni rediscover the relay.Ĭ. Concealed somewhere in the dense nebula formed by the supernova, the relay's position is effectively lost for centuries. 1800 BCE A supernova propels the Mu Relay, the only point of access to the remote Pangaea Expanse, out of position. In the resulting devastation, krogan society devolves into a collection of warring clans.Ĭ. In a global conflict, weapons of mass destruction are released, triggering a nuclear winter. 1900 BCE Tuchanka, the krogan homeworld, enters the nuclear age. The starship begins a journey throughout the galaxy which lasts for the next 8,000 years.Ĭ. 6000 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. 13,000 BCE The turians of Palaven begin to develop civilization around this time.Ĭ.

The Reapers methodically wipe out the remaining Protheans, as well as other contemporary races, and depart the galaxy to await the next cycle.Ĭ. Over the next several centuries, the Protheans fight the Reapers system by system, world by world, and city by city. 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. 48,000 BCE: Fall of the Protheans The Prothean Empire collapses with the arrival of the Reapers through the Citadel. The Prothean Empire is able to fend off the machines in a conflict known as the "Metacon War".Ĭ. To combat this threat, the Protheans aggressively assimilate many other spacefaring organic races into their empire. At some point, the Protheans encounter a hostile race of machine intelligences that endanger their existence. They go on to establish a galaxy-wide civilization linked by the mass relay network with the Citadel as their capital. The Protheans achieve spaceflight and discover mass effect technology from the ruins of the extinct inusannon. 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. 125,000 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. 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.Ĭ. 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. 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.Ĭ. 37,000,000 BCE An unknown spacefaring race fires a mass accelerator round at a Reaper near the planet Mnemosyne. Its corpse comes to rest on the planet Jartar and remains undisturbed for nearly one billion years.Ĭ. 1,000,000,000 BCE The Leviathan of Dis, a Reaper, is killed by the Leviathans. The Intelligence builds the mass relay network to increase the efficiency of the cycles, allowing galactic civilizations to develop faster and more consistently between harvests. 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 betrays the Leviathans, using its pawns to slaughter them for their genetic material to create Harbinger, the first Reaper. The Intelligence constructs an army of "pawns" to gather genetic information throughout the galaxy. 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 Leviathans consider themselves the galaxy's first and only apex race. The Leviathans dominate the Milky Way, enthralling every new sapient race they encounter and protecting them in return for tribute.
