Vincenzo Gioacchino Raffaele Luigi Pecci, pope 1878–1903. One of the most significant popes of the modern era. His encyclical Rerum Novarum (1891) established the foundations of Catholic social teaching — defending workers' rights, the living wage, and private property against both socialism and laissez-faire capitalism. He promoted Thomistic philosophy, opened the Vatican Archives to scholars, and navigated difficult relations with Bismarck's Germany.
- Lived: 1810 CE – 1903 CE
- Nationality: Italian
- Roles: Pope, Cleric
