In 1088 in Patmos, St. Christodoulos the Latrinos (a gifted and educated monk) was granted funds by the Byzantine Emperor Alexios I Komnenos, to establish a monastery in honor of Saint John the Theologian. In 1091, Christodoulos began the construction of the monastery over the ruins of a 4th-century basilica, also dedicated to Saint John.

The Monastery of Saint John the Theologian, built on top of Chora, dominates the whole island and looks like a Byzantine castle. It is surrounded by an irregular rectangular defensive enclosure, dating from the late 11th century until the 17th. Among other buildings the katholikon and cells have been preserved since the Byzantine period. The monastery’s walls are over 15 meters high, its length from north to south is 53 meters and from east to west 70 meters.

The library of the monastery and the rich collection of relics is considered really famous, the most important examples of which can be admired in the sacristy.

In 1999, the Monastery of Saint John the Theologian was declared a “World Heritage Monument” by UNESCO, along with the Holy Cave of the Apocalypse.

As my wife's ancestors lived on Patmos in the 18th century, we have visited the island a couple of times. Since we have an original letter from one of the abbots, we also visited the monastery, hoping for additional information. Unfortunately, nothing was found there at such short notice.