John was born in Normandy. He was ordained priest and spent many years preaching parish missions. He organized a congregation of nuns that grew into the Sisters of Our Lady of Charity, dedicated to the care of women rescued from a disorderly life, and a congregation of priests dedicated to the running of seminaries. He shared with St. Mary Margaret Alacoque the honor of initiating devotion to the Sacred Heart of Jesus (he composed the Mass for the Sacred Heart in 1668) and the Holy Heart of Mary, popularizing the devotions with his “The Devotion to the Adorable Heart of Jesus” (1670) and “The Admirable Heart of the Most Holy Mother of God”, which he finished a month before his death at Caen on August 19th. He was canonized in 1925.