Multi Species Empires?

[Mansen]

I was wondering if it could be possible to make multi-species empires that start with more than a single species of inhabitants? In a lot of Sci-Fi universes, planets are not inhabited by a single species (or even a handful) but a "cooking pot" of them.

Especially merchant empires or republics - The Sith empire (Which consists of conquered species from across the stars), Coruscant and Nar Shaddaa (Which are both essentially planetwide cities) from Star Wars spring to mind.

(This is strictly in a modding sense*)

[Nergal]

Next time, i started a game (Sluken, Hive Mind :p)and my home system was shared by another species, the Ketarov... Nothing special, in effect. But my homeplanet also was shared by the Ketarov !! So for the Sluken Hive Mind, i had 250M Ketarov slaves gniark gniark ! I don't know if it was normal, but it was cool
The only problem i have, it was 10 years later when the Sluken eat all my Ketarov Slaves ;'(

Sorry for any mistakes, i'm french :O