Macra Empire
From Tardis Wiki, the free Doctor Who reference
The Macra once held a "small empire" billions of years before 5000000053, when they were "the scourge of (the M87) galaxy," as the Tenth Doctor put it. He explained that they built up a small empire using humans as slaves and mining gas for food. The empire eventually declined and the Macra devolved into beasts billions of years later. (TV: Gridlock)
- It's unclear if the Doctor was referring to the Macra enslaved colony he visited as their empire, if they controlled other planets, or if he used "empire" metaphorically.
