BioWare didn't just build a game; they built a clock. A massive, ticking, cosmic clock that starts billions of years before Commander Shepard ever took a breath. If you've played the trilogy, you know the feeling of landing on a desolate rock and finding a Prothean ruin that makes you feel tiny. But honestly, the timeline of Mass Effect is way messier than the Codex makes it out to be. We tend to think of it as a straight line, but it’s more like a series of collapses.
Everything starts with the Leviathans. Imagine being the apex predator of the entire galaxy, so powerful that every other species basically worships you as a living god. That was their reality. They weren't just big; they were telepathic anchors of a galactic empire. But they had a problem. Their "lesser" thrall species kept building AI that eventually wiped them out. To fix this, the Leviathans built their own AI, the Intelligence, to preserve life at all costs.
Irony is a cruel mistress. The Intelligence decided the best way to "preserve" life was to harvest it before it could destroy itself. Around a billion years ago, the Intelligence slaughtered its creators and turned them into the first Reaper, Harbinger. This set the cycle in motion. Every 50,000 years, the Reapers return to "reset" the galaxy. It's a brutal, mechanical heartbeat that has defined the Milky Way for eons.
The Prothean Fallacy and the Real Ancient History
Most players think the Protheans were the first big deal. They weren't. Not even close. Before them, there were the Inusannon, the Thoi'han, and dozens of others we barely have names for. The timeline of Mass Effect is littered with the corpses of "great" civilizations. The Protheans were just the most recent ones to leave their trash lying around.
About 68,000 BCE, the Protheans achieved spaceflight. They weren't the benevolent sages the Council makes them out to be in 2183. They were imperialists. If you were a primitive species during their reign, you either joined the Prothean Empire as a second-class citizen or you were crushed. They were preparing for a war they knew was coming, but they didn't realize the Citadel—their seat of power—was a giant trap.
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By 48,000 BCE, the Reapers arrived. It wasn't a quick war. It took centuries. The Protheans fought room by room, planet by planet, until there was nothing left but ghosts and a few warning beacons. This is where the "modern" era of the timeline actually begins to take shape, long before humans discovered fire.
The Rise of the Council and the Rachni Mess
Fast forward to 580 BCE. The Asari find the Citadel. They're the first "modern" race to do it, followed closely by the Salarians. They form the Council, and for a while, things are chill. But the galaxy is never quiet for long.
The Rachni Wars (starting around 1 CE) nearly ended everything. The Council opened a relay into Rachni space and got swamped by a hive-mind bug race that couldn't be reasoned with. It was a slaughter. The Salarians, desperate for a solution, "uplifted" the Krogan. They gave a hyper-violent, fast-breeding species nuclear tech and spaceflight just to use them as cannon fodder.
- It worked. The Krogan ended the Rachni.
- Then, the Krogan started taking over the galaxy themselves because they had too many babies and not enough planets.
- This led to the Krogan Rebellions (700 CE).
- To stop the Krogan, the Turians were brought in, and the Salarians developed the Genophage—a biological weapon that basically sterilized the Krogan race.
It’s a dark, cyclical history of solving one problem by creating a bigger, more ethical nightmare. You see this pattern everywhere. The Quarians built the Geth in the 1890s CE because they wanted cheap labor. They got a revolution instead. By 1895 CE, the Geth had driven the Quarians into the Flotilla, and the Council just shrugged and closed the door.
Humanity Crashes the Party
Humanity is the new kid on the block, and we’re kind of annoying. In 2148, we found Prothean tech on Mars. A year later, we're at Charon, realizing our moon is actually a dormant Mass Relay. We exploded onto the scene.
The First Contact War (2157 CE) was basically a huge misunderstanding. The Turians saw humans trying to activate a dormant relay—which is illegal under Council law—and opened fire. We fought back. Hard. The Council eventually stepped in to stop the fighting, but the damage was done. The galaxy realized humans weren't going to sit quietly in the corner.
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Then comes 2183 CE. This is the "Now" of the original game.
- Saren goes rogue.
- Sovereign attacks the Citadel.
- Commander Shepard becomes the first Human Spectre.
- The galaxy finally learns that the Reapers aren't just a myth.
The two years between Mass Effect 1 and 2 are a weird gap. Shepard is dead (mostly), the Alliance is busy pretending the Reapers don't exist, and Cerberus is spending billions to bring back the only person who can stop the Collectors. By 2185, Shepard is awake, and the suicide mission against the Collector Base happens.
The Reaper War and the Andromeda Longshot
2186 CE is the end of the line. The Reapers arrive in force. Earth falls. Palaven burns. Thessia is leveled. The entire timeline of Mass Effect converges on a single point: the Crucible. This is where the 50,000-year cycle finally breaks, depending on the choices made at the finish line.
But while the Milky Way was screaming, there was a side project. The Andromeda Initiative. In 2185, right before the Reapers hit, four giant Arks left for the Andromeda Galaxy. They slept for 634 years. When they woke up in 2819 CE, the Milky Way they knew was ancient history.
This creates a dual timeline. You have the "Post-War" Milky Way—which we’re likely going to see more of in the upcoming Mass Effect sequel—and the "New Frontier" of Andromeda. It’s a lot to keep track of, but it’s what makes the universe feel lived-in.
Key Takeaways for Lore Hunters
If you're trying to master the lore, stop looking at the dates and start looking at the cause and effect. The Salarians are almost always the cause of the technical "fixes" that go wrong. The Turians are the muscle. The Asari are the diplomats who keep the secrets.
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- Check the Mars Archives: Most of what we know about the Protheans was filtered through what humans found in the Sol system.
- The Geth Perspective: Don't trust the Quarian version of the Morning War exclusively; Legion’s memories in ME3 provide a much more nuanced look at the 1890s.
- The Leviathan Factor: If you skip the DLC, the entire origin of the Reapers remains a mystery. It's essential for understanding why the timeline exists at all.
To truly understand where the series is going next, keep a close eye on the year 2190 and beyond. The "Destroy" ending (often considered the most likely canon path for a sequel) leaves the galaxy in a state of technological collapse. No Relays, no Citadel, no easy travel. The next chapter won't just be a continuation; it'll be a reconstruction of a timeline that was shattered by a billion-year-old AI. Keep your saves ready; the history is still being written.
Next Steps for Deep Lore:
- Re-read the "Planets" descriptions in the ME1 galaxy map; many contain dates for "pre-Council" civilizations that haven't been explored yet.
- Cross-reference the Andromeda "Heleus Cluster" history with the Milky Way's 2185 status to see exactly what the pioneers missed.
- Watch the "N7 Day" teasers from the last few years; the audio logs often hint at specific timestamps post-2186.