Revelation 17:12

12  And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast.

The ten horns are the ten world leaders that will receive a kingdom with the Beast. Whether they will be leaders of ten nations on the earth, or 10 zones in the area of the Old Roman Empire, or ten zones of the world is open to speculation. Both ten regional zones in the area of the old Roman Empire and ten world regional zones have been suggested by global think tanks like the “Club of Rome”. Both zone scenarios might be true. It might start with ten zones in the area of the old Roman Empire and then the revived Roman Empire becomes the head of ten world regional zones. We are getting pretty close to having ten regional economic unions around the globe already. In any case, the ten leaders give their power to the Beast. We are also told that three of the world leaders will be eliminated after the Beast/Antichrist comes to power.