This came out of a recent discussion with a few friends. We were talking about Russia and the Ottomans claiming to be the "Third Rome" for various reasons. I eventually got to wondering about how someone could get serious claims to being the "Third Rome". So the challenge is the following:
Have Russia be recognized as the Third Rome by Christianity, have the Ottomans eventually convince others that they are the Third and Islamic Rome (The first being pagan, and the second being Christian), and for serious bonus points and internet cookies, have the Umayyads or Moors/Almoravids take the bulk of western Europe (including Italy and Rome) and proclaim themselves the "new and true" Rome.
Three Empires, three Romes. Go.