When was the Book of Revelation Written ?

Eusebius book 3, chapter 23, verse 1

At that time the Apostle and evangelist John, the one who Jesus loved, was still living in Asia and governing the churches of that region, having returned after the death of Domitian from his exile on the island.

Domitiannus was emperor of Rome from 81 AD  to  96 AD.  John was sent to Patmos by emperor Domitianus  so even if John was sent early to Patmos in 81 AD this would still disprove the claim the Revelation was written in 67AD.  

Irenaeus in Against Heresies, 5.30.3