Joseph Nasi(João Nasi, Nassi, Mykas, Zuan Miques, Juan Sixs) (ca. 1520–1579), the nephew, son-in-law, and business partner of Gracia Nasi, was a powerful banker and trader. For his services as an adviser to two Ottoman sultans, he was awarded the duchy of Naxos in the Cyclades archipelago.

The son of a respected physician, Joseph Nasi was one of the most important traders in the Ottoman Empire. Born into a family of conversos, he and his younger brother Bernardo(Samuel, 1524?–159?) joined his uncle Diogo Mendes and his widowed aunt Gracia Na…