Pope Pius V, born Michel Perignon, was the 231st Pope of the Roman Catholic Church, serving from 1566 to 1572. He was born on January 17, 1504, and died on May 1, 1572. During his papacy, Pope Pius V implemented a series of religious reforms, including the restoration of the celibacy of the clergy, strengthening the power of the papacy, and opposing heretical ideas.