Revelation 17:9

Seven mountains. We have already observed that ancient Rome stood upon seven mountains. The same cannot be said of modern Rome, as some of the hills are not inhabited. --- The seven heads....are seven kings, or seven Roman emperors, who were particularly distinguished as the chief supporters of idolatry, and the most virulent persecutors of the Christian religion. Their names were Nero, Domitian, Severus, Decius, Valerian, Dioclesian and Antichrist. --- Five of them are fallen or gone, viz. Nero, Domitian, Severus, Decius, Valerian, who supported the idolatrous empire for a time; one is, viz. Dioclesian, with whom the reign of idolatry falls; and the other is not yet come, that is, antichrist.