Saint Alphonsus Maria de Liguori (27 September 1696 - 1 August 1787) was an Italian Catholic bishop who distinguished himself as a spiritual writer, scholastic philosopher and theologian.
Born into a noble family in Naples, Saint Alphonsus had a brilliant career in law before being ordained a priest. After that, he founded a religious order, the Congregation of the Most Holy Redeemer (called "Redemptorists") dedicated to work among the poor. In 1762 he was appointed Bishop of Sant'Agata dei Goti.
St. Alphonsus was a prolific writer, publishing nine editions of his "Moral Theology", in addition to other devotional and ascetic works, as well as many letters.
Saint Alphonsus was canonized in 1839 by Pope Gregory XVI. In 1871, Pope Pius IX proclaimed him Doctor of the Church (Doctor Zelantissimus).
Saint Alphonsus is one of the most read Catholic authors, he is also the patron saint of confessors.