DEFENSOR FIDEI. — Title conferred by Leo X, through the bull Ex supernae dispositionis arbitrio of 11 October 1521, upon Henry VIII of England, in recognition of the merits he had acquired in defending the Catholic faith through his work Assertio septem Sacramentorum contra M. Lutherum (1521).
The title was confirmed for him in 1523 by Clement VII; but it was subsequently withdrawn by Paul III, following the king’s schismatic defection. Nevertheless, a decision of Parliament in 1544 not only confirmed it to him but also declared it hereditary for all his successors. Even today it appears in the abbreviation d. f. on the royal coat of arms and on coins.