The following is from Foxe’s book of Martyrs. It shows what was the opinion of ancient Christians that the persecution of Revelation was in the 90s. The Nero date is relatively new.

“THE SECOND PERSECUTION UNDER DOMITIAN
The first Roman persecution beginning under Nero, as is aforesaid, ceased under Vespasianus, who gave some rest to the poor Christians. After whose reign was moved, not long after, the second persecution by the emperor Domitian, brother of Titus. Of whom Eusebius and Orosius so write, that he first beginning mildly, afterward did so far outrage in pride intolerable, that he commanded himself to be worshipped as God, and that images of gold and silver in his honour
should be set up in Capitolio. The chiefest nobles of the senators, either upon envy, or for their goods, he caused to be put to death, some openly, and some he sent into banishment, there causing them to be slain privily. And as his tyranny was unmeasurable, so the intemperancy of his life was no less. He put to death all the nephews of Jude, called the Lord’s brother, and caused to be sought out and to be slain all that could be found of the stock of David, (as Vespasian also did before him,) for fear lest he were yet to come of the house of David which should enjoy the kingdom. In the time of this persecution, Simeon, bishop of Jerusalem, after other torments, was crucified to death, whom Justus afterward succeeded in that bishopric. In this persecution John the apostle and evangelist was exiled by the said Domitianus into Patmos”

[Image: from Foxe’s book of martyrs: an edition for the people. In it he refers to Domitian as the third Nero]