Born to the nobility, the only son of Giovanna Battista Gigli and Leopoldo Marcucci. Francesco was drawn to the priesthood, but as he was an only child, his family objected. When his mother died, he moved to Rome, Italy. With the support of his aunt, Contessa Francesca Gastaldi, he studied in colleges run by the Jesuits, the Dominicans and the Franciscans, and made a special study of preaching. Met Saint Leonard of Port Maurice in April 1739, and was greatly influenced by his speaking style. Wrote Introduction on Evangelic Preaching in 1740. Ordained on 25 February 1741.
Named Apostolic Missionary by Pope Benedict XIV in July 1742. Founded the Congregation of the Pious Workers of Mary Immaculate on 8 December 1744. Father Francesco helped teach the new sisters and served as their spiritual director. Organized schools, published text books, and worked for the education of women.
Reluctant bishop of Montalto, Italy, chosen in 1769 and consecrated on 15 August 1770; he felt unworthy, and did not want to leave the work he was already doing. Friend of Saint Paul of the Cross who predicted that Francesco would be recognized as a saint. As bishop he travelled to parishes to preach to his flock, and conducted religious retreats for his priests. He was a hands-on administrator who encouraged his clergy to be ministers first and foremost.
Titular Patriarch of Constantinople on 10 December 1781. Confessor and advisor to Pope Clement XIV. Worked to finish construction of the church of the Immaculate Conception during a period of persecution by anti-Church forces of the French Revolution. All the good that he accomplished over the years he attributed to the direct intervention of the Blessed Virgin Mary.
- 12 July 1798 in Montalto delle Marche, Ascoli Piceno, Italy of natural causes
- relics in a chapel in the Church of the Immaculate Conception, Montalto delle Marche
- “Venerable Francesco Antonio Marcucci“. CatholicSaints.Info. 16 April 2015. Web. 13 February 2016. <>