Pope Leo XIII (born Vincenzo Gioacchino Raffaele Luigi Pecci) served as the 256th Pope of the Catholic Church from 1878 to 1903, making him one of the longest-reigning popes in history. Born on March 2, 1810, in Carpineto, Italy, he died on July 20, 1903, in Rome. He is renowned for establishing modern Catholic social teaching through his landmark encyclical Rerum Novarum (1891), which addressed workers' rights and became a foundation of Catholic social doctrine. Leo XIII promoted Thomistic philosophy and worked to reconcile the Catholic Church with the modern world.
