John Leonardi came into this world in 1541, the youngest of seven children born to middle-class parents in the Tuscan region of Lucca Italy. From childhood, he manifested a desire to seek solitude and to give himself to prayer and meditation. At age 17, he began his ten-year study to become a certified pharmacist's assistant at Lucca. Afterwards, he studied for the priesthood and was ordained in 1572. He first dedicated himself to the Christian formation of adolescents in his local Lucca parish. He also gathered a group of laymen about him to work in hospitals and prisons. Leonardi worked with this group to spread devotion to the Blessed Mother as well as devotion to the Forty Hours and spreading the message of the importance of frequent reception of the Eucharist. He became interested in the reforms issued by the Council of Trent, and he proposed a new congregation of secular priests to convert sinners and restore Church discipline. In 1583, his association, which became known as the Lucca Fathers, was recognized by the bishop of Lucca with the approval of Pope Gregory XIII. In 1595, the congregation was confirmed by Pope Clement VIII, who then appointed him to reform the monks of Vallombrosa and Monte Vergine. He assumed the name of "Giovanni of the Mother of God" as his religious name. This foundation received approval from Pope Paul V on January 14, 1614, when the pope, encouraged by the cardinal protector Giustiniani, issued a Papal decree approving the union of the Lucca Fathers with the Piarists and their founder St. Joseph Calasanz. This union would last only until the beginning of 1617 when Paul V would issue another decree making the Piarists their own separate religious congregation. Civic leaders in Lucca opposed the establishment of a new religious order and acted to stop its formation. While ultimately ineffective, their efforts forced John Leonardi to spend most of the remainder of his life outside Lucca, with special exceptions granted by its government under the influence of the Pope. In 1621, his community would formally be designated Clerks Regular of the Mother of God. John was aided by both his spiritual director St. Philip Neri and by St. Joseph Calasanz. The final Rule of his institute was published in 1851. Two houses of the Clerks of the Mother of God were opened when he died and three others were opened during the seventeenth century. John died in Rome on October 9, 1609 from the great plague, which he contracted while ministering to those stricken by the influenza epidemic. He was venerated for his miracles and religious fervor, and in 1603, along with Cardinal Vives, he founded the seminary for the Propagation of the Faith for the philosophical and theological training of missionary Priests. His memory was held so high in the Holy City that Pope Leo XIII had his name placed in the Roman Martyrology and ordered the Roman clergy to celebrate his Mass and Office, an honor which is otherwise strictly limited to beatified Popes.