In Warhammer 40k, the first contact with xenos is the moment humanity met alien life and it went badly. That encounter set the tone for the Imperium’s brutal, paranoid stance on every non-human species.
What the first contact with xenos actually means
The phrase covers humanity’s earliest recorded meetings with alien civilisations, long before the Imperium existed. These weren’t peaceful handshakes. They were violent, confusing, and often one-sided.
In the lore, the first contact with xenos isn’t a single event. It’s a pattern that repeats across human history: discovery, betrayal, war. That pattern shaped the Imperium’s belief that aliens can never be trusted.
- It predates the Imperium and the Emperor’s rise.
- It happened during humanity’s Dark Age of Technology and the Age of Strife.
- It’s remembered as a warning, not a milestone.
Why it matters to the Imperium
The Imperium treats xenos as a permanent threat. That attitude traces back to early encounters where aliens either attacked human worlds or exploited them during humanity’s collapse.
The Emperor’s Great Crusade was partly a response to this. He wanted to unite humanity and wipe out alien threats before they could finish the job. The first contact with xenos became justification for genocide on a galactic scale.
- It fuels the Imperium’s xenophobia and its endless wars.
- It justifies the Great Crusade’s extermination campaigns.
- It’s used to keep humans loyal and afraid of the outsider.
How it connects to other lore
The first contact with xenos ties into the Horus Heresy, the Age of Strife, and the rise of the Chaos Gods. Alien civilisations like the Eldar and the Orks were already ancient when humanity first met them.
It also links to the Tau, who are a much later xenos race, and the Tyranids, who are a far worse threat. The Imperium’s response to all of them is shaped by that original trauma.
| Xenos race | First contact context | Imperium’s response |
|---|---|---|
| Eldar | Ancient, declining empire | Distrust, occasional alliance |
| Orks | Always at war | Extermination |
| Tau | Recent expansion | Suspicion, containment |
| Tyranids | Extragalactic invasion | Total war |
What the sources say (and don’t)
The Fandom pages we tried to fetch were blocked, so this summary draws on widely known 40k lore. Some details vary by source, especially exact dates and which species were encountered first.
What’s consistent is the outcome: humanity learned that the galaxy is hostile, and the Imperium never forgot.
Key facts
- The first contact with xenos predates the Imperium and the Emperor.
- It happened during humanity’s Dark Age of Technology or the Age of Strife.
- The encounter was violent, not diplomatic.
- It shaped the Imperium’s xenophobic doctrine and the Great Crusade.
- Exact details vary by source, but the outcome is always war.
FAQ
When was the first contact with xenos?
It happened during humanity’s Dark Age of Technology or the Age of Strife, long before the Imperium. Exact dates aren’t fixed in the lore.
Which xenos race did humanity meet first?
Sources disagree. The Eldar and Orks are the most commonly cited, but it’s not a settled point.
Why does the Imperium hate xenos?
Early encounters were violent and exploitative. That trauma became doctrine, and the Imperium now treats all aliens as enemies.