St Alphonsus Liguori
St. Alphonsus Liguori entered the priesthood in 1726, and later founded the missionary Congregation of the Most Holy Redeemer. He wrote his first book at age forty-nine and went on to author more than one hundred books on spirituality and theology over his lifetime. Many of these books were written during the half-hours snatched between his labors as missionary, religious superior, and Bishop. He died in 1787, at age ninety-one. St. Alphonsus was beatified in 1816, canonized in 1839, and declared a Doctor of the Church in 1871.