Alfonso de Liguori was an Italian bishop and theologian born on September 27, 1696. He founded the Congregation of the Most Holy Redeemer, also known as the Redemptorists, in 1732. Alfonso is known for his work in pastoral care and his emphasis on the importance of moral theology. He was canonized as a saint by Pope Gregory XVI in 1839 and declared a Doctor of the Church in 1871. Alfonso de Liguori is celebrated for his writings, particularly in the areas of spirituality and moral guidance, and his feast day is observed on August 1.