[Cronos]

The seven heads of the beast are the first seven emperors: Augustus, Tiberius, Caligula, Claudius,Nero, Vespasian, Titus

The seventh, revelation says " his reign will be short" - Titus' reign was 2 years (AD 79 to 81).

The eight, Domitian is the one who started the second persecutions of Christians -- the book says "And the beast which was and is not: the same also is the eighth, and is of the seven, and goeth into destruction". -- because many thought Domitian was Nero returned -- Juvenal, a Roman author (pagan) called Domitian a second Nero calvus Nero

[circlecity]

"The seven heads of the beast are the first seven emperors: Augustus, Tiberius, Caligula, Claudius,Nero, Vespasian, Titus"

I believe there were three emperors not mentioned here between Nero and Vespasian: Galba, Otho and Vitelius.