Pius V was a 16th-century Italian pope and Dominican friar who led the Catholic Church from 1566 until his death in 1572. Born Antonio Ghislieri, he served as a bishop and inquisitor before his election to the papacy. He is primarily recognized for his rigorous implementation of the Council of Trent's decrees and his efforts to reform church discipline. His leadership was central to the Counter-Reformation, during which he worked to standardize liturgy and defend Catholic orthodoxy against Protestantism and Ottoman expansion.