The Papacy of St. Pius V ( 1566-1572 ) was known not only for its focus on halting heresy and worldly abuses within the Church , but also for its focus on improving popular piety in a determined effort to stem the appeal of Protestantism . The Papacy of St. Pius V ( 1566 -- 1572 ) was known not only for its focus on halting heresy and worldly abuses within the Church , but also for its focus on improving popular piety in a determined effort to stem the appeal of Protestantism .