The Xenophontos Monastery is one of the oldest monastic establishments on the peninsula of Mount Athos, located on the southwest coast between the monasteries of Panteleimon and Docheiariou. Relations with the latter were frequently troubled by disputes over property and relative rank in the Athonite hierarchy.
Founded before the end of the 10th century by the monk Xenophon, the monastery was originally dedicated to St. George. Small at first, in the last quarter of the 11th century the monastic complex was restored and enlarged by a second ktetor, the megas droungarios Stephen, a eunuch; by that time Xenophontos housed 55 monks. After a period of decline in the 13th century following the Fourth Crusade, Xenophontos recovered its prosperity in the early 14th century under the energetic leadership of the hegoumenos Barlaam. From around 1425 onward, the monastery again entered a period of obscurity, during which it came under the control of Slavic monks. In addition to land on the Holy Mountain, the Xenophontos monastery owned property in Thessaloniki, the Chalkidike peninsula, and Lemnos.
The archive at Xenophontos preserves 33 acts of Byzantine date, ranging from 1089 to 1452. The library contains 27 Byzantine manuscripts. Numerous elements of architectural sculpture in the "old katholikon" of the monastery have been attributed to the period of the church's construction; its templon, however, has been regarded as belonging to the reconstruction phase sponsored by the megas droungarios Stephen.
Oxford Dictionary of Byzantium