http://www.pfrs.org/preterism/pret01.html
There were only two Roman emperors who persecuted Christians on a large scale in the first century, Nero and Domitian. The other Emperors were either indifferent to Christianity, or did not consider it a serious threat to Rome. The first Roman persecution under Nero took place in the decade of the 60s, just before the fall of Jerusalem. Nero was responsible for the deaths of both Peter and Paul in Rome in AD67, Peter by crucifixion, and Paul by being beheaded.
There is no record of Nero’s banishing Christians to Patmos, only his brutality against the Christians of Rome. It was Nero who made a sport of throwing Christians to the lions for the entertainment of the crowds, and who burned many at the stake along the road leading to the Coliseum merely to light the entrance.
After Nero’s death Rome left the Christians alone until the rise of Domitian to power in AD81. Although not as cruel and insane as Nero, Domitian had some Christians killed, the property of Christians confiscated, Scriptures and other Christian books burned, houses destroyed, and many of the most prominent Christians banished to the prison island of Patmos.
All ancient sources, both Christian and secular, place the banishment of Christians to Patmos during the reign of Domitian (AD81-96). Not a single early source (within 500 years of John) places John’s banishment under the reign of Nero, as preterists claim. All modern attempts to date Revelation during Nero’s reign rely exclusively on alleged internal evidence, and ignore or seek to undermine the external evidence and testimony of Christians who lived about that time, some of whom had connections to John.
Bingo ---
The earliest most credible witness for the 96 AD date is Irenaeus whose source, among others, would have been Polycarp, bishop of the church at Smyrna that received one of the seven letters that John wrote in 96 AD.
The Preterists are so far out on a limb on this one that they fall into the category of Agnostics, historical and biblical.