A peculiar title belonging to the sovereign of England, as that of “Catholic” to the king of Spain, and that of “Most Christian” to the king of France. These titles were originally given by the popes of Rome; and that of Defensor Fidei was first conferred by Pope Leo X. on King Henry VIII., as a reward for writing against Martin Luther; and the bull for it bears date quinto Idus Octob., 1521. Enc. Lond.