When was Revelation written?
Now a lot of the problem about interpreting this is that we in the modern world don't realise that the names of the Roman Emperors, at least the ones we call them, may not be their real "names" and were not necessarily "titles" etc. --> for example, "Nero" was born "Lucius Domitius Ahenobarbus", he was adopted by Claudius and became "Nero Claudius Caesar Drusus Germanicus" and then took the TITLE "Augustus" when he was made Emperor
Note that Caesar was the name adopted by those from Caesar's "family" -- Augustus (who was born Octavian and took the TITLE Augustus) was Caesar's grand-nephew and adopted son, hence he had the name Caesar. Tiberius, Augustus' adopted son was born "Tiberius Claudius Nero" and adopted as "Tiberius Julius Caesar"! Then you had Caligula whose name we know "Caligula" was actually a nick-name given to him as a kid when he wore little shoes (Caligulae!) with the troops in Germany when he accompanied his father Germanicus
anyway, the point is that Nero's name also contained "Domitius" -- while the guy we call Domitian (who was Roman Emperor from 81 to 96) was called "Titus Flavius Caesar Domitianus "!
As a side note -- even the "Emperors" before 300 AD weren't called that - their official position was "princep" or first citizen. The "imperator" word meant field-marshall.
Anyway, so we've seen that the other Christian writers place this in the time of the guy we call "Nero" and if we examine Iraeneus closely he says that this was during Domitian's time, but he would know the names of emperors etc. a lot better than we English speakers 2000 years later knew -- so was this "Domitius Nero" he referred to? I think it's a lot more probable.
My opinion is that it was written in the 60s AD, under the persecution of Nero. Because there is no evidence for persecution under Domitian in the later years of the 1st century.