And so it was that John, the "apostle that Jesus loved," (John 21:20), who was given the responsibility of caring for Mary the mother of Jesus Christ for the rest of her life after the Jesus' Crucifixion (John 19:26-27), and who wrote the Gospel of John (John 21:24), found himself exiled on Patmos. There, he had one more important job to do.
The island of Patmos is today part of Greece. It is located among the Sporades group of islands in The Aegean Sea near the west coast of Turkey. It is a relatively small member of the group, measuring only about 6 by 10 miles (10 by 16 kilometers), with a very irregular coastline.
The Romans (see Ancient Empires - Rome) used Patmos, and numerous other places like it, as a place for political prisoners. According to Eusebius, John was sent to Patmos in the year 95 by the Roman emperor Domitian (see New Testament Roman Emperors), but was released less than 2 years later. Since he, and all of The Twelve Apostles were roughly the same age as Jesus, John would by that time have been well over 90 years old - making him very likely the only apostle to survive to old age. All the rest were martyred much earlier (see What Happened To The Apostles?).
Fact Finder: What warning did Jesus Christ give to those who would add to, or take away from, the prophecies in the Book of Revelation?