史前时期 (未知BCE - 1,000,000,000 BCE)[]
未知 BCE
利维坦主宰着整个银河系,奴役和保护所有他们见过的新物种,以此来换取贡品。利维坦认为他们自己是银河系中第一个且唯一一个位于顶峰的种族。
在看到他们的奴仆种族创造的合成体生命总是叛变后,利维坦创造了一个AI去寻找一个永久保留有机生命的方法。AI建造了一支“龙虾”军队去获取整个银河系的基因信息。
AI背叛了利维坦,用它自己的龙虾军团去屠杀利维坦并获取了利维坦的基因,以此建造了先驱者,第一个收割者。因此收割者开始了银河系的高等有机生命收割循环,很大程度上这是AI为了完成它的任务而做的一个大型试验。
AI建造了质量效应中继器网络来加快循环的效率,让银河系的文明能飞速发展以便于更好地收割。
前普洛仙时期 (1,000,000,000 BCE - 68,000 BCE)[]
1,000,000,000 BCE
- 迪斯的利维坦,一个收割者被利维坦消灭,它的尸体被遗留在行星贾塔上并且在近十亿年里没有被打扰。
37,000,000 BCE
- 一个不知名的星际种族,使用质量加速器朝Mnemosyne行星附近的一个收割者开火。炮弹贯穿了收割者并且摧毁了它,然后持续在太空中飞行,最终击中了Klendagon行星且创造了被称为大裂谷的地质现象。
298,000 BCE
- 古代种族Arthenn在Zelene星系中繁荣发展,住在Helyme行星上直到被一个毁掉了所有星球上复杂生物的不知名的事件彻底摧毁。他们也在星系的其它星球上活动过,比如Epho,一个有着被轨道轰炸过痕迹的星球。还有Gaelon,在上面可能有过氦-3燃料开采的活动。
125,000 BCE
- 古代星际种族thoi'han和伊努山隆在Eingana行星上开展,使得行星上布满了上百艘舰船的残骸。精炼零号元素被损坏的引擎驱动核心反射到了环境中,造成了许多当地物种的灭绝,而幸存下来的物种展现出了学习异能的趋势。
前议会时期 (68,000 BCE - 500 BCE)[]
68,000 BCE
- 普洛仙发展出了星际航行的能力,从灭绝的伊努山隆文明遗迹中发现了质量效应科技。他们建立了一个泛银河系文明,依靠质量效应中继器网络来相互连接,首都则是神堡。
- 在某个时间点,普洛仙遭遇了一个带有敌意的并且会危害他们存在的机械种族。为了应对威胁,普洛仙强行同化其他星际航行种族且并入了他们的帝国。普洛仙帝国现在有能力去应对这场冲突,这场冲突被命名为“Metacon战争”。
48,000 BCE: 普洛仙的陨落
- 普洛仙帝国因为收割者通过神堡来入侵而解体。尽管普洛仙从之前的文明遗迹中了解到了收割者的存在,还做了准备,但依然防不胜防。在接下来几个世纪中,普洛仙在一个接一个的星系,星球,城市中对抗收割者。但在最后还是寡不敌众,收割者不紧不慢地灭绝剩余的普洛仙人还有其他同一时期的种族,最后离开了银河系等待下一个收割轮回。
13,000 BCE
- 帕勒汶的突锐人发展出了文明。
6000 BCE
- 一个外星种族为了躲避他们自己的恒星爆炸,制造了一艘由AI控制的星舰,搭载了超级电脑且里面包含了一个虚拟世界。超过十亿的外星人将他们的意识转存到虚拟世界中。这艘星舰在接下来的8000年中一直在整个银河系中穿梭着。
1900 BCE
- 克洛根人的母星图岑卡进入了核子时代。在一场全球性的冲突中,大规模杀伤性武器被肆意使用而导致核冬天的到来。在最后克洛根社会退化到了氏族部落时代。
1800 BCE
- 超新星爆发使得通向Pangaea Expanse的唯一入口-缪中继器偏离了位置。考虑到超新星爆发后留下的稠密星云,中继器的位置应该已经失踪几个世纪了。之后,雷克耐重新发现了这个中继器。
580 BCE
- 基于普洛仙科技发展出了超光速星际航行技术后,阿莎丽人开始探索质量效应中继器网络,最终找到了诸多中继器的中心-神堡空间站。
520 BCE
- 赛拉睿人发现了神堡,开始与阿莎丽人会晤。
议会时期 - 形成 (500 BCE - 1 CE)[]
500 BCE: 建立议会
- 神堡议会建立。阿莎丽人和赛拉睿人合作管理申报并且将它建设为一个银河系社区的中心,由议会领导。这一年也被称为0 GS,银河系标准纪年的开始(Galactic Standard (GS))。
- 为了向新盟友阿莎丽人示好,赛拉睿联盟公开了神兵联队的存在。神兵联队受到威胁后作出的答复是刺杀每一个联盟内阁成员,随后STG成立并开始消灭神兵联队。
- 第一次与沃勒人接触。最终神堡议会委托沃勒人起草联合银行法案,用于建立统一银河系货币-星币,并且关联整个银河系经济。
- 突锐统一战争打响。正在快速成长且孤立和仇外的各突锐边疆殖民地彼此之间开战。在长达数年战争后,突锐最高族长介入停止了一切势力间的战争。不过突锐殖民地彼此间的仇恨仍然持续了数十年。
- 议会授予沃勒人在神堡上开设第一个非议会种族大使馆的席位的荣誉,而不是给他们一个议会席位。
- 与巴塔瑞人第一次接触,他们在一个世纪后被授予大使馆席位。
- 阿莎丽人发现艾柯人的母星星系,帮助艾柯人激活了附近的质量效应中继器。在一个艾柯人的生命周期时间内他们建立了与神堡的常规贸易路线,并被授予大使馆席位。
- 与哈纳人和奎丽人的第一次接触,两个种族不久后都被授予了大使馆席位。
议会时期 - 战争和叛乱 (1 CE - 900 CE)[]
1 CE: 雷克耐战争
- 雷克耐,一个智力高度发的的蜂巢思维式虫族被一支神堡探险队在一次打开未激活的质量中继器时发现,中继器连接雷克耐的恒星系。雷克耐之后被证明是一个敌对种族并且开始了一场对抗整个银河系的战争。因为无法与布满毒素的雷克耐世界地下巢穴取得联系,因此与雷克耐女王谈判是不可能的。
80 CE
- 雷克耐战争继续,赛拉睿人第一次与克洛根人接触并且开化了原始的克洛根人,教导他们成为了神堡议会的士兵。克洛根人有能力在恶劣的雷克耐居住的环境中生存,并且把雷克耐赶回了它们的巢穴,有序地根除雷克耐女王和卵。
300 CE
- 雷克耐被宣布灭绝,为了感谢克洛根人在雷克耐战争中所做的贡献,议会奖励了他们一颗新的星球以摆脱图岑卡的恶劣环境,克洛根人口因此爆炸式增长。
300 - 700 CE
- 克洛根人开始大规模扩张,殖民了更多的星球。为了应对他们的增长,神堡建立了特种战术与侦查部,也就是幽灵部队。
693 CE
- Beelo Gurji, 一个赛拉睿人探员,被神堡议会任命为第一个幽灵。
700 CE: 克洛根叛乱
- 克洛根军阀任由雷克耐战争的老兵去吞并其它神堡世界的种族领地,最终议会要求他们从阿莎丽殖民地Lusia撤离,但是克洛根人拒绝了。幽灵部队针对克洛根人基建设施执行了一次先发制人的打击,克洛根叛乱开始。
- 神堡议会第一次接触突锐人并且把他们带进了战争中,在第一次突锐进攻之后,克洛根人作出的答复是利用大规模杀伤性武器摧毁了突锐人殖民地。突锐人发誓要阻止克洛根人以绝后患。
- 在突锐人加入银河系社区后,沃勒人答应成为突锐帝国的附属国。
710 CE
- 在意识到了克洛根人只要有源源不断的兵力就无法被阻止,突锐人释放了赛拉睿人制作的生物武器-基因噬体,克洛根人口开始下降。
800 CE
- 克洛根叛乱结束,尽管克洛根的骚扰仍然持续了数十年。突锐人取代了克洛根人神堡维和部队的地位。
- 在这次冲突之后,神堡议会起草了神堡公约。
议会时期-扩张 (900 CE - 2157 CE)[]
900 CE
- 突锐人因为阻止克洛根叛乱取得了神堡议会的席位。
1400 CE
- 由于工业的过度发展导致了德雷尔母星Rakhana环境恶化。
1600 CE
- 第一次出现有在界神星系目睹收集者的报告。在神堡世界中,官方宣布这是谣言和传说。
1755 CE
- 萨马拉的三个女儿被诊断为阿达亚克西。蕾拉和法勒里同意了被驱逐,但是莫林斯逃走了。萨马拉成为了一名阿莎丽惩恶使并且在接下来430年中持续追逐她的女儿。
1880 CE
- 阿利亚T洛克来到欧米伽,一个界神星系中的空间站,某种意义上是界神星系的非官方首府。阿利亚被空间站的军阀雇佣为副手并很快成为了他手下中最受信任的副官之一。
1895 CE: 黎明战争
- 奎丽人制造出来的廉价劳动机器桀斯产生了自我意识,因为害怕桀斯会起义奎丽人开始销毁它们。桀斯于是起身反抗它们的创造者。在这场被桀斯命名为黎明战争的冲突中,奎丽人被一个接一个有序地赶出了自己的家园,幸存的奎丽人被迫开始星际流浪,居住在移民舰队上。与预料中的相反,桀斯并没有继续向神堡空间中扩张,而是将自己隔绝了起来,躲在英仙座幕区后面。神堡议会关闭了奎丽人在神堡上的大使馆作为惩罚。
1921 CE
- 桀斯开始建造超级建筑以便用来供桀斯生存和模拟所有现存的桀斯程序。完成超级建筑的建造会最大化桀斯集体意识的空间,这是桀斯文明的长久计划。
1961 CE
- 4月12日,尤里加加林乘坐东方一号称为第一个到达太空的人类。地球人开始成为一个星际种族。
1969 CE
- 7月20日,阿波罗11号登陆月球,尼尔阿姆斯特朗成为第一个在月球上行走的人类,也是第一个在非地球天体上行走的人类。
1980 CE
- 阿利亚T洛克在打败了军阀之后取得了欧米伽的控制权,她给成为手下败将的克洛根人起了个“族长”头衔,用他提醒着敌人自己的力量。
1985-1992 CE
- 欧空局的第一个深空任务乔托号发射成果,飞掠了哈雷彗星和葛里格-斯克杰利厄普彗星。
1990 CE
- 哈勃太空望远镜发射。
1992 CE
- 欧空局发射尤利西斯号环绕太阳。
2000 CE
- 德雷尔人与哈纳人初次接触,因为他们的家园环境极其恶化德雷尔人在2025年前经历了一次人口骤降。哈纳答应帮助他们,进行了一次大规模疏散将375000名德雷尔人带到Kahje。在接下来数十年剩余的110亿德雷尔人在母星上挣扎,耗尽了所有的食物和水。
2015 CE
- SpaceX 成功回收猎鹰九号的第一级。这是人类的第一次火箭回收活动,商业航天的时代到来。
2069 CE
- 7月20日,为了纪念登月100周年,人类在沙克尔顿坑留下了第一个永久居住地。
2070 CE
- 亿万富翁 Victor Manswell 赞助人类太空探索事业,斥资巨额到他自己的私人太空探索企业。
2075 CE
- 曼斯维尔远征队从地球出发,踏上了前往半人马座阿尔法星的旅程,船上300名殖民者全部处于休眠状态。但在不久后地球方面就和他们失去了联系。
2077 CE
- 莉亚纳T苏妮出生。
2103 CE
- The European Space Agency's Lowell City in Eos Chasma becomes the first permanent human settlement on Mars.
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.
2129 CE
- Alec Ryder is born.
2134 CE
- Steven Hackett is born.
2137 CE
- David Anderson is born.
- The Eldfell-Ashland Energy Corporation demonstrates helium-3 fuel extraction from the atmosphere of Saturn.
2139 CE
- Saren Arterius is born.
- Kahlee Sanders is born.
2143 CE
- Construction of Gagarin Station (Jump Zero) begins beyond the orbit of Pluto.
2146 CE
- Thane Krios is born.
2147 CE
- 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 lighttravel and beginning detailed exploration of the Sol system.
2149 CE
- 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.
2150 CE
- 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.
2151 CE
- 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.
2152 CE
- 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 Primeand Terra Nova.
- Thane Krios is submitted for training as an assassin under the hanar.
2154 CE
- April 11: Shepard is born.
- There is a second publicized accident involving the exposure of humans to element zero.
2155 CE
- 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.
2156 CE
- Arcturus Station is formally inaugurated.
- A small number of human children exposed to element zero exhibit minor telekinetic abilities.
- Kai Leng is born.
2157 CE
- 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.
Council Era - Advent of Humanity (2157 CE - 2183 CE)[]
2157 CE: The First Contact War
- 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.
- The events of Mass Effect: Revelation begin. Admiral Jon Grissomtravels 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.
- The events of Mass Effect: Evolution occur. 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.
2158 CE
- 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.
2159 CE
- 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.
2160 CE
- 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.
2161 CE
- 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.
2162 CE
- 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.
2163 CE
- 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.
- Alec Ryder's twin children are born.
2164 CE
- 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.
2165 CE
- 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. In 2165 CE, 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.
- The events of Mass Effect: Revelation continue. 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 batariansupporter, 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.
2166 CE
- Commander Vyrnnus, a turian mercenary, is hired to oversee the training of human biotics at BAaT.
2167 CE
- 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.
2168 CE
- Kaidan Alenko accidentally kills Commander Vyrnnus after being provoked. The diplomatic fallout with the turians results in BAaT being shut down a year later.
- Shepard receives secondary exposure to element zero. Permanent biotic inclination manifests.
2170 CE
- 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 bioticchildren 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.
2171 CE
- In protest at the refusal of the Citadel Council to limit human expansion in the Skyllian Verge, the batariansclose their embassy, withdraw into their home systems, and effectively become a rogue state.
- Shepard is officially detected as a biotic and fitted with L3 implants.
- 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.
2172 CE
- April 11: Shepard enlists in the Alliance military.
- November 14: Kai Leng enlists in the Alliance military.
- On Gagarin Station, "Eliza" becomes the first sapient AI created in the Systems Alliance.
2173 CE
- 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.
2174 CE
- Ashley Williams enlists in the Alliance military.
2175 CE
- 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.
2176 CE
- 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 biotictraining program, the Ascension Project.
- The Anhur Rebellions, a civil war waged over the practice of slavery, begin on the human and batariancolony world of Anhur and spread throughout the Amun system. Abolitionism supporters hire the Eclipsemercenary group to fight the batarian pro-slavery Na'hesit faction.
- James Vega enlists in the Alliance military.
- Kai Leng is awarded the N7 designation by the Alliance's Interplanetary Combatives Academy, but later that year he is dishonorably discharged and imprisoned for first-degree murder.
- 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.
- The Andromeda Initiative, a privately-funded multi-species endeavor created to explore and colonize the Andromeda Galaxy, is founded.
2177 CE
- 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.
2178 CE
- 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.
- A lethal airborne virus sweeps through the quarian Migrant Fleet. Tali'Zorah nar Rayya's mother is among the casualties.
- The Anhur Rebellions end with the abolitionist forces in power, and the reconstruction of Anhur commences.
2182 CE
- Admiral Kahoku of the Systems Alliance begins investigating suspected Cerberus activities.
2183 CE
- 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.
- The events of Mass Effect: He Who Laughs Best occur. Jeff "Joker" Moreau is assigned as the pilot of the SSV Normandy.
Mass Effect (2183 CE - 2186 CE)[]
2183 CE: The Eden Prime War
- The events of Mass Effect occur. 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 Sovereignto return its kind to the galaxy. While Shepard follows Saren through the legendary Mu Relay to the Conduit, Sovereign and a geth fleet assault the Citadel. Shepard defeats Saren and the Alliance Navy destroys Sovereign, preventing the release of the Reapers. The Citadel Council is irrevocably changed by Shepard's decisions.
- The events of Mass Effect Galaxy occur. Jacob Taylor and Miranda Lawson prevent an assassination attempt on the Citadel Council by batarian terrorists.
- The events of Mass Effect: Incursion occur. Aria T'Loak interrupts a meeting between Blue Sunsmercenaries and the Collectors on Omega, and learns that the Collectors have a dangerous interest in humanity.
- The events of Mass Effect 2 begin. One month after the Battle of the Citadel, the SSV Normandy is attacked and destroyed by an unidentified assailant, resulting in the death of Commander Shepard. Later, the Systems Alliance officially declares Shepard "killed in action".
- L4 biotic implants are developed.
- The events of Mass Effect: Ascension occur. Two months after the Battle of the Citadel, galactic society is still in flux over the changes to the Council and kept unaware of the true nature of Sovereign, the Citadel, and the mass relays. Cerberus pushes ahead with plans for both the Ascension Project and the quarianMigrant Fleet, but is foiled by the actions of Kahlee Sanders and Paul Grayson. After an attack by Cerberus forces, the Migrant Fleet changes its conservative policy, sending ships away from the Flotilla to look for new homeworlds or possibly a dormant Reaper.
- The events of Mass Effect: Redemption occur. Commander Shepard's body is recovered by Blue Sunsmercenaries for the Shadow Broker, who has been hired by the Collectors. Cerberus eventually obtains the body with the help of Liara T'Soni and begins work on the Lazarus Project.
- The events of Mass Effect: Paragon Lost begin. The Systems Alliance dispatches several special forces units to aid the colony of Fehl Prime, which is under attack by Blood Pack forces. Most units are shot down before landing, but Delta Squad survives and defeats the Blood Pack. The Alliance assigns Delta Squad to guard the colony.
2184 CE
- January 1: The Andromeda Initiative airs a recruitment ad titled "Come With Us".
- January 15: Singapore Marketing Council debates on whether to air the Andromeda Initiative ad on their juristiction. Council members suspect peculiar behind-the-scenes happenings and so allow the ad on the pretext of getting their own people to find out the Initiative's secrets.
- June 1: The Andromeda Initiative brainstorms another recruitment ad prospectively titled "A New Future Awaits".
- The Eden Prime War comes to a close. Although most geth forces in Citadel space were destroyed in the Battle of the Citadel, holdouts yet remain. The Alliance Navy reduces its patrols, relying instead on civilian ships to report any geth activity. Raids are carried out against identified geth outposts, but the conflict is essentially over.
- The raloi of the planet Turvess launch their first space telescope and discover the asari cruiser Azedes in their system. The asari make first contact with the raloi, who are formally welcomed into the galactic community the following year.
- The biological weapon EHE, or "exotic humanoid encephalopathy", is used by the human terrorist organization Totenkopf in an attack on Gagarin Station. The Alliance cruiser SSV Manila is deployed to monitor the asteroid Israfil, the supposed origin of the miroorganisms used to produce EHE.
- The freighter MSV Estevanico is attacked by Blood Pack mercenaries and crashes into the planet Zanethu. The Alliance crew on board were among the first humans to encounter the vorcha race.
- A clone of Commander Shepard, developed by Cerberus for testing purposes alongside the original's under reconstruction body, is stolen by the deserter Rasa from the Lazarus Research Station.
- L5 biotic implants are developed.
- July 25: The Andromeda Initiative orientation briefing is shown to prospective candidates.
- December :The events of Mass Effect Andromeda: Initiation begin.
- December 27: Khalisah al-Jilani enjoins people to watch her expose about the Andromeda Initiative in two days' time.
- December 29: Fehl Prime's disappearance becomes known to the general public although Collectorinvolvement is still seen as a conspiracy theory. Cora Harper's retrieval of Andromeda Initiative technology from HOME Group's Home Away space station is reported as a security breach by "a rival corporation". Al-Jilani Investigates: Andromeda... Exposed! is recorded, its production notes indicating a focus on Alec Ryder's career.
- December 31: Armali Children's Almanac informs readers about differing human attitudes to new year festivities.
2185 CE
- The events of Mass Effect: Paragon Lost continue. Fehl Prime is attacked by the Collectors after a Cerberus agent hoping to discover their intentions signals them. Most of Delta Squad is lost during the battle for the colony, but they succeed in disabling the Collector ship. Delta Squad member James Vega chooses to rescue the asari Treeya, who possessed vital intel on the Collectors, leaving the colonists to die aboard the Collector ship when it crashes on the planet's surface.
- The events of Mass Effect 2 continue. Commander Shepard is revivedand tasked by the Illusive Man to investigate the mysterious disappearances of entire human colonies in the Terminus Systems. Investigation of the attacked colony of Freedom's Progress reveals the enigmatic Collectors from beyond the Omega 4 Relay to be responsible for the disappearances. After assembling a capable team, Commander Shepard uses a captured Reaper IFF to safely traverse the relay and infiltrate the Collector base. Shepard succeeds in eliminating the Collector threat, saving humanity throughout the galaxy from certain destruction.
- February 10: A dangerously close flyby of the comet CR1331 Kingu devastates the hanar colony of Belan.
- February 15: Rumors of Commander Shepard's activities on Omega surface although downplayed as hallex-induced hallucinations. Xenophobic Homeward Sol group implicated in bombing "a shuttle"; Nightside News in a Minute neglects to mention the shuttle was docked to the Andromeda Initiative's Ark Hyperion at the time.
- March 28: A coalition of the corporations Binary Helix, Sonax Industries, and Guanghui Solutions invades the krogan and vorcha-populated world of Garvug.
- April 28: The Vallum Blast annihilates much of the capital city of the turian colony of Taetrus. In retaliation, Taetrian colonial and Turian Hierarchy troops declare war on the separatist group responsible for the attack.
- August 11: The Citadel Council makes first contact with a race of virtual aliens who offer advanced technology in exchange for help maintaining the supercomputers that run their civilization.
- Liara T'Soni locates the Shadow Broker's concealed base on the planet Hagalaz. The Shadow Broker, exposed as a yahg, is killed. Liara takes control of the Broker's organization, intending to use the Broker's vast information network to aid Shepard's fight against the Reapers.
- December 7: Biologists discover the kirik, an insect-like species with biotic capabilities, on the arid world of Ekram. After the kirik exhibit signs of intelligence, experts and officials debate whether or not the kirik should be uplifted.
- The Andromeda Initiative begins its journey to the Andromeda galaxy, with the first wave, made up of the Nexus, Ark Hyperion, Ark Leusinia, Ark Natanus, and Ark Paarchero, launching into dark space. A second wave comprised of Ark Keelah Si'yah is expected to launch not long after.
2186 CE
- January 12: An asari exploration team discovers a lost human colony in the Alpha Centauri system. The Systems Alliance links the colony to the forgotten Manswell Expedition of 2070 and establishes contact with the colonists.
- January 23: SSV Budapest, an Alliance cruiser that sparked a diplomatic crisis between the Earth Systems Alliance and the Batarian Hegemony, withdraws from the Bahak system.
- The Bahak system is subsequently destroyed following the explosion of its mass relay. An asteroid was sent to the relay in order to delay the Reapers' invasion. Hundreds of thousands of batarians living on Aratoht are obliterated in the blast.
- The events of Mass Effect: Retribution occur. Six months prior to the start of the story, Systems Alliance hero Jon Grissom dies. Hundreds of dignitaries attend Grissom's funeral and a memorial plaque dedicated to him is placed in the Jon Grissom Academy.
- After three years on the run, Paul Grayson is captured by Cerberus and implanted with Reaper technology. Kahlee Sanders and David Anderson attempt to rescue Grayson by persuading the Turian Hierarchy to raid several vital Cerberus installations, but are unaware Grayson's body is now under Reaper control. Once free, the Reapers learn of the Ascension Project and use Grayson to single-handedly attack Grissom Academy, where he is finally killed by Anderson and Cerberus assassin Kai Leng. In the aftermath, Anderson and Sanders decide to study Grayson's body to discover how to combat the Reapers.
- The events of Mass Effect: Inquisition occur. Councilor Udina asks Captain Bailey to investigate Executor Pallin, claiming that C-Sec has been compromised and is working against the Citadel Council. The investigation results in Pallin's death and Bailey's promotion to the rank of Commander, but Bailey is left with reservations about Pallin's guilt.
- The events of Mass Effect: Deception occur. Gillian Grayson seeks revenge against Cerberus and the Illusive Man for the death of her father. With the help of a faction of biotic supremacists, she captures Cerberus assassin Kai Leng to lure the Illusive Man out of hiding by holding Leng for ransom. Her plan fails, however, and Leng kills her and escapes.
- The events of Mass Effect: Conviction occur. Admiral Anderson travels to Omega to recruit Alliance marine James Vega to guard Commander Shepard as the Commander is taken to trial for the destruction of the Bahak system.
- The events of Mass Effect: Invasion occur. Aria T'Loak defends Omega from Adjutants unleashed by Cerberus. The Adjutants distract Aria from Cerberus's true plan: to conquer Omega and maintain exclusive access to the Omega 4 Relay. Aria realizes this and unites the disparate gangs and mercenaries of the station to repel the Cerberus invaders, but is outsmarted by Cerberus's General Oleg Petrovsky. When he threatens to destroy Omega, Aria accepts exile and Cerberus takes control of the station.
- The events of Mass Effect: Infiltrator occur. When a Cerberus alien experimentation facility known as the Barn is attacked by turian forces, Randall Ezno, a Cerberus operative enhanced with biotic implants, learns the truth about the horrific nature of the experiments and discovers his own handler has been made a test subject. Randal turns against Cerberus and the Barn's Director, fights his way through the facility, and escapes. He provides the Systems Alliance with intel on his former employers and swears revenge on the Director.
- September 21: A massive influx of batarian ships in the Exodus Cluster reported by the Alliance News Network. The newcomers claim their home systems are under attack from an as-yet unidentified hostile adversary. Khar'shan is reported to be under bombardment and the Harsa relay blockaded.
- September 28: Taetrus goes dark, the culprits confirmed to be the same forces behind the attack on the batarians. Primarch Fedorian declares the Turian Hierarchy at war.
- The events of Mass Effect 3 begin. Six months after the destruction of the Alpha Relay, the Reapers invade the galaxy through batarian space and attack Earth. Commander Shepard escapes and discovers a Prothean superweapon design on Mars that could end the Reapers' threat once and for all.
- October 5: Hierarchy offensive to retake Taetrus reported as failed: four turian fleets dispatched to the Mactare relay, Reaper ships emerge from the Trebia relay in a push toward Palaven. Primarch Fedorian alerts the galaxy to prepare for spotty communications due to destruction of comm buoys during wartime.
- The events of Mass Effect 3 continue. To build the Crucible and take back Earth, Commander Shepard and allies embark on a journey to unite the various races in the midst of a galaxy-wide war. During the final confrontation with the Reapers over Earth, the Commander makes a decision that changes the galaxy forever.