Pope Leo XIII, born Vincenzo Gioacchino Raffaele Luigi Pecci in 1810, was the head of the Catholic Church from 1878 until his death in 1903. Known for his progressive views, he addressed social issues such as workers' rights, labor conditions, and advocated for social justice. He also focused on education, promoting the compatibility of faith and science. His encyclical Rerum Novarum is considered a foundational document of Catholic social teaching. Leo XIII's reign was characterized by diplomatic efforts to reconcile the Church with modernity.