Joseph Bryennios (Greek: Ἰωσήφ Βρυέννιος; 1350 – 1431/38)) was a learned Byzantine monk of the 15th century. He was a monk at the Monastery of Stoudios. He wrote many important works of scholarship in support of Orthodoxy, and against the Union of Churches. He died sometime between 1431 and 1438. Source: Wikipedia (en)