Regnans in Excelsis

by Pope Pius V

50 pages, Unknown Binding

First published February 25, 1570

About the author

Pope Saint Pius V born Antonio Ghislieri (from 1518 called Michele Ghislieri, O.P.), was Pope from 8 January 1566 to his death in 1572. He is venerated as a saint of the Roman Catholic Church. He is chiefly notable for his role in the Council of Trent, the Counter-Reformation, and the standardization of the Roman rite within the Latin Church. Pius V declared Thomas Aquinas a Doctor of the Church.

As a cardinal, Ghislieri gained a reputation for putting orthodoxy before personalities, prosecuting eight French bishops for heresy. He also stood firm against nepotism, rebuking his predecessor Pope Pius IV to his face when he wanted to make a 13-year-old member of his family a cardinal and subsidize a nephew from the papal treasury.

By means of his papal bull of 1570, Regnans in Excelsis, Pius V excommunicated Elizabeth I of England for heresy and persecution of English Catholics during her reign. He also arranged the formation of the Holy League, an alliance of Catholic states. Although outnumbered, the Holy League famously defeated the Ottoman Empire, which had threatened to overrun Europe, at the Battle of Lepanto. Pius V attributed the victory to the intercession of the Blessed Virgin Mary and instituted the feast of Our Lady of Victory.