The Monastery of John the Forerunner of Constantinople/Istanbul (AD 462)
In 462, a Roman aristocrat named Studius moved from Italy to Constantinople and founded the Monastery of John the Forerunner, dedicated to John the Baptist. The monks of this monastery were often called Stoudites or Studites.
With more than 1,000 monks, the Monastery of John became one of Constantinople’s most import- ant and influential monasteries. The monks of the Monastery of the Sleepless Ones joined the Monastery of John after it was built in 462. The monasteries of Mount Athos adopted many of the rules of the Monastery of John, as did other monasteries around the world. The monks of the Monastery of John opposed bishop Acacius and the Henoticon, and also the imperial anti-icon policies of the 700s and 800s.
The monastery was destroyed by Roman Catholic crusaders in 1204 and was not fully restored until 1290. However, the monastery was again destroyed when the Ottoman Turks conquered Constantinople in 1453, and was converted into the İmrahor Mosque in 1486. Although it became a museum in 1946, it was once again made a mosque in 2014. Today, the ruins of the monastery are located in the Fatih district of Istanbul, near the Marmara Sea.