Leonard of Chios
Leonard's birth is of an uncertain date on the Island of Chios, then under Genoese domination and died in either Chios or in Italy in 1482. He himself says he was of humble parents, and he entered the Dominican Order in Chios. After this profession he was sent to Padua for his philosophical and theological studies. After his ordination he taught at both Padua and Genoa, then at the request of Maria Justiniani returned to his native island, and was made Bishop of Mytilene on Lesbos Island by Pope Eugene IV.
The Byzantine Emperor Constantine XI had sent a request to the pope, asking that efforts be made to effect a union between the Latin and 'Greek' (Orthodox) Churches: for this purpose Leonard was selected to accompany Isidore, Cardinal Bishop of Sabine, to Constantinople. Some degree of success was attained through their efforts and a treaty was ratified in December, 1452. However, the Latins refused to provide large scale aid to the Byzantines, and in the following year Leonard witnessed the devastation of the city as the Ottoman Turks took the city, led by the Sultan Mehmed II "the Conqueror". Leonard and the Cardinal were miraculously spared from the slaughter which ensued, the latter returning to Rome while Leonard to his diocese. From Chios, he wrote to the Pope a detailed account of the fall of Constantinople in a letter, which is often reprinted by historians ("Historia captae a Turcis Constantinopolis", Nuremberg, 1544; P.G., CLIX, 923 sq.; Lonicer, "Chronica Turcica", I, Frankfurt, 1578: "De capta a Mehemete II. Constantinopoli Leonardi Chiensis et Godefredi Langi narrationes," ed. L'Ecuy, Paris, 1823).
He governed his diocese for the next three years, until Lesbos also fell to the Turks and he was taken captive to Constantinople. He obtained his freedom the following year, and immediately wrote the Pope a description of the sack of his diocese ("Leonardi Chiensis de Lesbo a Turcis capta epistola Pio Papae II missa", ed. Hopf, Konigsberg, 1866).
His best-known writings are the two letters mentioned above and an apologetical tract in answer to the humanist Gian Francesco Poggio Bracciolini. Both tracts with biographical sketches were edited by Michael Justinian (Avila, 1657). There is reason to believe that many of his letters remain unedited in the Vatican Library.