For example, in Revelation 17 it describes the imminent destruction of Jerusalem by one of the "seven kings" who is "an eighth king" and belongs to the "ten kings."
they are also seven kings, five of whom have fallen, one is, the other has not yet come, and when he does come he must remain only a little while. As for the beast that was and is not, it is an eighth but it belongs to the seven, and it goes to destruction. And the ten horns that you saw are ten kings... (Revelation 17:10-12a)In 65AD, there had indeed been the succession of five kings of Rome (1. Julius; 2. Augustus; 3. Tiberius; 4. Claudius; 5. Caligula) and the sixth king Nero, was now reigning and creating havoc for both Jerusalem and Christians throughout the Empire. And indeed the his successor, Vespasian, would eventually put Jerusalem to "destruction". Vespasian was amazingly the next Emperor of the United Roman Empire, making him the 7th king. But before he took office there were three would-be Emperors, Galba, Otho and Vitelius, who in one way constituted an attempt to unite the Empire under their kingship. In this sense, Vespasian was "an eighth king". But if these three would-be Emperors are counted individually, then Vespasian was one of the "ten kings".
John's apocalyptic prophecy of the immediate future of his people was therefore uncannily fulfilled. I discuss this, and other amazing historic references to the complete fulfilment of Revelation chapters 1 - 19 in my eBook- "The Most Embarrassing Book In The Bible - Understanding The Book of Revelation" available from www.andrewcorbett.net.