John of Patmos is the name traditionally given to the author of the Book of Revelation. The text of Revelation states that John was on Patmos, a Greek island where, according to most biblical historians, he was exiled as a result of anti-Christian persecution under the Roman emperor Domitian.
Christian tradition has considered the Book of Revelation's writer to be John the Evangelist, supposed author of the Gospel of John. However, a minority of senior clerics and scholars, such as Eusebius, recognize at least one further John as a companion of Jesus, John the Presbyter. Some Christian scholars since medieval times separate the disciple from the writer of Revelation.