St. Paul of the Cross was born Paul Francis Danei at Ovada in the republic of Genoa in 1694. His parents, Luke and Anna, were both exemplary Catholics and instilled in young Paul a respect for the sacraments and often read aloud the lives of the saints to their numerous children. St. Paul's childhood was marked by austerity and penitence. He would often sleep on the bare ground and spend long hours in prayer. In all these practices he was imitated by his brother John Baptist, his junior by two years.

In the Summer of 1720, in three extraordinarily vivid visions, St. Paul saw a black robe with Jesus' name in white characters, surmounted by a white cross, emblazoned on the breast. In the third vision the Blessed Mother, attired in the habit, encouraged St. Paul to found a community that would mourn continually for the passion and death of her Son. After getting authorization to follow his vocation, St. Paul made a forty day retreat in a triangular room at St. Charles's church at Castellazzo living on just bread and water. It was here, without aid of earthly guide, that he wrote the rule.

After assisting at Castellazzo for a short time, St. Paul made his way barefoot and penniless to Rome where he would present himself to the Vatican. As he had not thought of providing himself with an introduction or credentials, St. Paul was turned away.

St. Paul made his way home and along the way visited the solitary slopes of Monte Argentaro. In 1727 St. Paul and John Baptist would return to Monte Argentario to start their first house of retreat. The many hardships they endured did not prevent them from finally opening their first Passionist Retreat (as their Monasteries were called) in 1737.