The long stay of the Apostle and Evangelist John at the island of Patmos and his Apocalyptic vision in the Holy Cave sanctified the island and established it as one of the most important pilgrimages of Christendom. When Christianity spread and prevailed at the islands, during the 4th, 5th and 6th centuries, a lot of Christian basilicas were erected. Obviously, during this period, more than one basilica would have been built on the island. The biggest of all would have occupied the place of the ancient temple of Artemis, and must have been dedicated to Saint John the Theologian. The existence of this early Christian church is attested by the early findings right outside the walls of the monastery.
This is the upper part of the marble plaque of the consecration of the early Christian basilica of Saint John the Theologian. The inscription testifies for the existence of the early Christian church and reads as follows:
The inauguration, that is the sanctification of the holy altar of the glorious Apostle and Theologian John, took place during the time of his Holiness the bishop Epithymetos, the 13th of the 5th month of the 5th indiction, the construction successfully completed by Theodosios [...]