At the beginning of 1354 Gregory Palamas (1296-1359), the Archbishop of Thessaloniki, was captured by the Ottomans, according to Philotheos Kokkinos in the Vita of Saint Gregory, while on a trip to Constantinople from Thessaloniki to reconcile the controversy between Ioannis V Palaeologos and Ioannis VI Kantakouzenos. He spent a year in captivity and during that time wrote an epistle to his flock back in Thessaloniki describing his experiences. He was finally released in March of 1355. Palamas refers that he was jailed and suffered from hardships, only when he was transported from one place to another. The Turks did not put him in prison but they were setting him free only when he was visiting the region of Anatolia, in order to gain the compassion of Christian population, who would take pity on him and would contribute to the payment of the ransoms. They dragged them around to the regions of the Ottoman State, such as Lampsakos, Piges, Bursa, finally to the summer resort of Orhan. There Palamas engaged in two theological discussions; the first one with the grandson of Orhan, ?smail and the second one with a group of well-educated men from Orhan’s court, the “atheist Chiones”. The third theological debate occurred in July of 1354 in ?znik with a representative of the Muslim religion, called Tasimanis. Regarding to his three theological debates, Palamas, apart from some isolated hostile incidents against him, he was treated with respect gaining the same time the sympathy of the Muslims interlocutors. The content of this pastoral letter is of a great interest because it is sheds light on Ottoman practice of captivity in the 14th century, on Palamas’s impressions of his Turks captors, and the circumstances under which he set free. Palamas’s epistle is also valuable as a source for the study of Byzantine anti-Islamic policy and perhaps allows us to understand better how a Byzantine scholar and theologian of the period viewed the Ottomans in a period in which the Byzantine Empire was loosing more and more to the Turks in Anatolia. Generally speaking a study of Gregory Palamas’s epistle offers the possibility of contributing to a better historical understanding of Ottoman history in the mid-14th century, a period for which not a great deal is known and for which there is a paucity of Turkish sources.