Illithid Arrivals

 

Where'd mind flayers first show up (major) in cannon (non-jammer). 

Outside of Spelljammer, the setting treats mind flayers as already ancient, hidden, and pre–recorded history.

But if you stitch together Realms-specific sources (2e–5e, Underdark, Lords of Madness, Serpent Kingdoms, Grand History of the Realms, Dragon Magazine), you can narrow it to a few strongly implied “first arrival zones.”

 

🧠 The Best-Supported Answer (Realms Canon Synthesis)

The earliest meaningful Illithid presence in Forgotten Realms is:

The Deep Underdark beneath Faerûn — during the Days of Thunder (~−30,000 DR or earlier)

That’s the era when:

• The creator races (sarrukh, batrachi, aearee) dominated
• Empires rose and fell long before elves or humans

👉 By the time recorded history begins, Illithids are already entrenched below the world.

 

🌍 Primary “First Arrival” Candidates

1. The Deep Underdark (Most Canon-Supported)

Nearly every Realms source agrees:

• Illithids were already present in the deepest layers
• They built vast subterranean empires long before drow civilization
• These empires later collapsed or fragmented

Supporting lore:

• Lords of Madness (3.5e)
• Underdark (3.5e)
• Drizzt novels (implicitly)
• Grand History of the Realms

👉 Interpretation:

They didn’t “arrive” during recorded history—they were already there when history began.

 

2. The Sarrukh Empire Zones (Days of Thunder Connection)

From Serpent Kingdoms and related lore:

• The Sarrukh ruled vast empires (e.g., Okoth)
• These empires collapsed catastrophically

Where Illithids fit:

• Some texts imply Illithids:
• Moved into the ruins afterward
• Or may have been competing hidden powers even then

👉 Key theory:

The collapse of the creator races may have:

• Opened the Underdark
• Allowed Illithids to expand or emerge into prominence

 

3. The Imaskar Region (Ancient Surface Interaction)

While not their origin, this is one of the earliest surface-adjacent interactions:

• The Imaskar empire (−8000 DR onward)
• Known for planar experimentation and slavery

Illithid connection:

• Later lore suggests:
• Illithids encountered or manipulated ancient human empires
• Possibly influenced or observed Imaskar

👉 Important:

This is not where they arrived, but one of the first times they brush against surface history.

 

4. Oryndoll — The First “Known” Great City

Oryndoll is crucial:

• One of the oldest and largest Illithid cities in Faerûn
• Located deep beneath the Shining South

Why it matters:

• It represents:
• The height of Illithid civilization in the Realms
• Likely a remnant of a much older empire

👉 Many DMs interpret Oryndoll as:

• Not the origin point
• But a surviving capital of their earliest expansion

 

🌀 So Where Did They ACTUALLY “Arrive”?

Here’s the cleanest canon-consistent answer:

❗ They did not “arrive” during recorded Realms history

Instead:

• Illithids likely entered Toril:
• Before −30,000 DR
• Possibly via:
• Time travel (consistent with broader lore)
• Planar intrusion (Far Realm angle)
• Unknown ancient migration
• By the time the first civilizations appear:
• They are already:
• Underground
• Organized
• Ancient

 

🧩 Reconciling With Non-Spelljammer Lore

Even without Spelljammer:

• Lords of Madness strongly implies:
• Illithids are not native in the conventional sense
• Realms texts avoid contradicting:
• The “ancient beyond memory” framing

👉 So the setting deliberately leaves this gap:

They are older than the world’s memory—and possibly older than the world itself.

 

🎯 Bottom Line

If you need a definitive, table-ready answer:

• Location of first arrival:
  → The Deep Underdark of Faerûn
• Time:
  → Pre–Days of Thunder (before −30,000 DR)
• Earliest major center:
  → Oryndoll
• Certainty level:
  → Intentionally ambiguous, bordering on unknowable