St. Peter Canisius, SJ, Priest and Doctor of the Church, (May 8, 1521 – December 21, 1597) is celebrated December 21. He was Dutch and his given name was Pieter Kanis. He became known for his strong support for the Catholic faith during the Protestant Reformation. He founded 18 colleges and authored 37 books; his catechisms went through 200 printings in his lifetime alone. The restoration of the Catholic Church in Germany after the Protestant Reformation is largely attributed to the work there of the Society of Jesus, which he led. An important aspect of his faith and historic legacy was his veneration of the Blessed Virgin Mary and contribution to the Hail Mary.
Canisius taught that, while there are many roads leading to Jesus Christ, for him the veneration of the Blessed Virgin Mary was the best. His sermons and letters document a clear preoccupation with Marian veneration. Under the heading "prayer" he explains the Hail Mary prayer as the basis for Catholic Marian piety. Less known are his Marian books, in which he published prayers and contemplative texts. To the Hail Mary he added the sentence, Holy Mary, Mother of God, pray for us sinners, which was not at that time commonly recited after the Angelic Salutation. Eleven years later it was included in the Catechism of the Council of Trent of 1566.
Canisius published an applied Mariology for preachers, in which Mary is described in tender and warm words. He actively promoted the sodalities of our Lady and the rosary associations. Theologically, Canisius defended Catholic Mariology in his 1577 book, De Maria Virgine Incomparabili et Dei Genitrice Sacrosancta Libri Quinque.