Athanasius the Athonite (c. 920 – c. 1003), also called Athanasios of Trebizond, was a Byzantine monk who founded the monastic community on Mount Athos, which has since evolved into the greatest centre of Eastern Orthodox monasticism.
He studied at Constantinople and became famous there as Abraham. By the time Nikephoros II Phokas, Byzantine Emperor from 963 to 969, ascended the imperial throne, Abraham, ill at ease with the lax morals of the monks living in the capital, changed his name to Athanasios and joined the monks at Mount Kyminas in Bithynia. In 958, he relocated to Mount Athos.
Athanasius went to Mount Athos in Greece, where he aided Emperor Phocas, a longtime friend, in repelling the Saracens who were invading the region. Successful in this military campaign, Athanasius received financial backing from his friend to found a monastery on Mount Athos in 961.
Upon the Byzantine Emperor's death the enemies of Athanasios prevailed and he had to leave Athos for Cyprus, where he lived until the new emperor, John Tzimisces, resumed the patronage of the Great Lavra and bestowed upon the monastery its first charter in 971. Athanasios, spurred by a divine vision, returned at once to Athos.