No, no you misunderstand. In the Metaverse one can create an empire, which is a collection of folks whose scores are combined to give an empire score. Empires are then ranked against each other based on that score. It has been a feature since since GC1, so waiting for Brad to chat about it on the front page won't be happining.
As DA said it appears that an emperor has sent you an invite to join his/her empire, the link would have been to that empire's Metaverse page.
