Pope Leo XIII’s papacy focused on addressing the social issues brought about by industrialization. He issued the encyclical *Rerum Novarum*, which laid the foundation for Catholic social teaching, emphasizing the rights of workers. Birth name: Gioacchino Vincenzo Raffaele Luigi Pecci Nationality: Papal States, Kingdom of Italy Born: March 2, 1810 Died: July 20, 1903 Pontificate: February 20, 1878 – July 20, 1903