Pope Leo XIII, born Vincenzo Gioacchino Raffaele Luigi Pecci on March 2, 1810, was the head of the Roman Catholic Church from 1878 until his death on July 20, 1903
. He was the 257th pope and had the fourth-longest papal reign in history. Leo XIII is best known for his intellectualism and efforts to reconcile the Catholic Church with modern ideas and social issues. He sought to define the Church's position on modern thinking and was a strong advocate for workers' rights. His 1891 encyclical Rerum Novarum laid the foundation for the Church's modern social doctrine, emphasizing fair wages, safe working conditions, and the right to form trade unions, while opposing both atheistic socialism and unregulated capitalism. This earned him the nicknames "Social Pope" and "Pope of the Workers"
. He also promoted Thomism (the theological system of Thomas Aquinas), Marian devotion, the rosary, and the scapular. Leo XIII opened the Vatican Secret Archives to scholars and founded the Vatican Observatory, demonstrating openness to science and scholarship. He was the first pope not to have ruled the Papal States, which had been lost in 1870, and worked to maintain the Church's spiritual authority despite that loss
. His papacy is remembered for its pastoral concern for social justice, engagement with modernity, and efforts to improve relations between the Church and civil governments. He died at age 93 and was buried in the Vatican
. In summary, Pope Leo XIII was a reform-minded and intellectual pope who shaped the Catholic Church’s social teachings and sought to bridge faith with modern societal challenges.
