In this book, the first major conflict between Venice and the Ottoman Empire is presented, ten years after the Fall and the collapse of the Byzantine Empire (1453), marking the beginning of a competition between the two powers that would last until the 18th century. The struggle for dominance in the southeastern Mediterranean served as the launching pad for the First Venetian-Ottoman War, dragging the Greek populations living in the areas where the battles took place, with the main focus being the Peloponnese. Issues such as the relations between the Republic of St. Mark and the Ottoman Empire before the outbreak of war, the diplomatic processes during it, as well as the attitude of the Greek populations, are examined in this monograph. The work is complemented by the presentation of archival documents, as well as translated excerpts from the work of the historian Giacomo Bosio, "Storia della Religione di San Giovanni Gierosolimitano", and tables of rulers and officials, accompanied by relevant bibliography and an illustrative appendix.