ABRAVANEL, ISAAC (1437–1508), known as Abravanel, Abrabanel, and Abarbanel; Spanish-Portuguese biblical commentator, theologian, and philosopher. Born in Lisbon into a wealthy Jewish family from Seville, Isaac ben Judah Abravanel succeeded his father as the treasurer to Alfonso V, king of Aragon, but in 1483 for political reasons he had to flee to Castille, where he remained in the service of Ferdinand and Isabella until the expulsion of the Jews on May 31, 1492. He then moved to Naples in the service of King Ferrante I until a French invasion forced him to flee with the king to Messina in 1494. Isaac resided in Corfu until 1496; then moved to Monopoli (Apulia), and in 1503 settled in Venice, where he spent the last years of his life.

Isaac's earliest work, composed when he was in his teens, was Tsurot ha-yesodot (Forms of the elements). His next, completed around 1465, was ʿAteret zeqenim (Crown of the...