Five have fallen: If these kings represent Roman emperors, and we start counting from the change from a republic to an empire with Augustus, who ruled from 29 BC to AD 14, then the fifth would be Nero, who ruled from AD 54 to 68, the sixth would be Vespasian, and the seventh would be Titus. The eighth king would be Domitian.
that was, and now is not: Early commentators argued that Domitian embodied Nero’s spirit (see study note on Revelation 17:8).
the other seven: This seemingly unbeatable ruler was also destined for destruction.