He was born Bogdan John Mandic, in Castelnovo, Dalmatia (Bosnia-Hercogovina) Yugoslavia on May 12, 1866. He was the twelfth child of a Croatian family who once had great wealth but had lost nearly all. Having come from a family that had lost all its wealth gave him a great compassion for those who fell on hard times. Having had a harsh and abusive experience going to confession as a child made him want to express God's gentleness and compassion. He joined the Capuchins of the Venetian Province taking the name, Leopold. After his ordination to the priesthood, he ardently desired to return among his people to promote the union of the Church, but his superiors entrusted him with the ministry of confessor, which he fulfilled in an exceptional way throughout his entire life.
Leopold died in Padua on July 31, 1942. He was beatified by Pope Paul VI on May 2, 1976 and canonized by Pope John Paul II on October 16, 1983. Leopold is hailed as the “Apostle of Unity”.