St John the Divine was banished to Patmos by the pagan Roman Emperor Domitian in AD 95. Living as a hermit in a cave above what’s now Skala, St John heard the voice of God issuing from a cleft in the rock and transcribed his terrifying visions as the Book of Revelation where he 'saw a beast rise up out of the sea, having seven heads and 10 horns...'. From these events Patmos became known as the 'Holy Island' or, less appealingly, 'the island of the Apocalypse'.
Around 1000 years later, in 1088, the Byzantine Emperor Alexis I Komninos gave the Blessed Christodoulos permission to erect a monastery in John’s memory. Pirate raids necessitated powerful fortifications, so the monastery took the form of a mighty hilltop castle. In the centuries that followed, Patmos became a semi-autonomous monastic state and achieved such wealth and influence that it was able to resist Turkish oppression.