Born in San Fele, south of Naples, in 1800 to a wealthy family, Justin de Jacobis joined the Vincentians in 1818 in Naples and was ordained in 1824. His early priesthood was spent primarily as a preacher of missions and retreats in his native region. He tirelessly ministered to the sick during the Cholera epidemic of 1836-37 in Naples.

His reputation as a preacher and his personal devotion to prayer led some in authority to mention the possibility of ordaining Justin a bishop, a position he did not want. In order to derail this plan, Justin petitioned his superiors for an assignment in the foreign missions. Justin was appointed Prefect Apostolic of Abyssinia and all the Neighboring Territories.

Ethiopia had been Christian since the 4th century, but decades of schism and heresy left the country with no Catholics. Justin and companions adopted Ethiopian dress, became accustomed to the food, and learned the languages of the areas. Initially, they opted not to be seen praying in public, due to threat of immediate execution if discovered.

As Ethiopians came to Justin for catechesis and formation for ordination, Justin insisted that they remain in the Ethiopian Coptic Rite, a position which was unpopular at the time but was affirmed at Vatican II. Finding a bishop to ordain the candidates for priesthood was a challenge. The Holy See recognized Justin’s abilities and secretly ordained him a bishop in 1849.

Justin encountered many difficulties, including harassment and imprisonment instigated by the Orthodox Coptic Bishop. In 1860, the Ethiopian King decreed that Catholicism be banned and Justin was imprisoned for several months. After a forced march to Halai in southern Eritea, he spent his remaining month doing mission work along the Red Sea. He was canonized in 1975 and is patron saint of Africa. His feast day is July 31.