He was born around 1300 in Thessaloniki and was named Fokas. His mother was Jewish. He was meticulously educated by Thomas Magistros, whom he also served as a servant. He becomes a monk at Mount Sinai and from there he moves to the Holy Mountain. Initially he stayed at the Vatopedi monastery where he met St Sava, the Crazy One for Christ, whom he wrote his biography. Then he stayed at the monastery of Great Lavra where he met with St Gregory Palamas. In 1342 he succeeded Macarius in the leadership of the monastery. Right from the outset he espoused St Gregory’s views on the hesychastic issue. In 1342 he wrote to discourses: ‘On the Tabor light’ and ‘Against Akindynos’. In 1347 he was elected Metropolitan of Erakelia. In 1351 he took part in the Holy Synod on the hesychastic issue on the side of Gregory Palamas and kept the minutes. He ascended to the Throne of the Ecumenical Patriarchate twice from 1353-4 and 1364-76. He compiled the akolouthia of St Gregory Palamas having recognized his sanctification and settled once and for all the hesychastic issue, justifying Palamas. As a Patriarch, he hightened the fame of the Church worldwide and worked zealously against the Ottoman threats and the Latin propaganda. The then Pope rejected his proposal to hold an ecumenical Synod to correctly reunite the two Churches. He is the author of numerous works which include biographies of the Saints Gregory Palamas, Sava from Vatopedi, and wrote letters on the Saints Anysias, Demetrius the Myrrh Bearer, the Three Hierarchs, John Crysostomos and others. He also wrote treatises on the liturgies and the canons, on history, poetry etc. and on all issues relating to the entire field of Theology. He was renowned as a conscious theologian, a wonderful synaxarist and hymn writer. He fervently spoke out in favour of Orthodoxy and defended Orthodox views in various fora. In his old age he stepped down from the throne of the Patriarchate and reposed in 1379.