A biography of Pope Leo XIII (1810-1903), who served as head of the Catholic Church from February 20, 1878 to his death on July 20, 1903. At age 93, Vincenzo Gioacchino Raffaele Luigi Pecci was the oldest reigning pope, and had the third-longest confirmed pontificate, behind those of Pius IX (his immediate predecessor) and John Paul II. Pope Leo XIII was well-known for his intellectualism and his attempts to define the position of the Catholic Church with regard to modern thinking. In his famous 1891 encyclical Rerum novarum, he outlined the rights of workers to a fair wage, safe working conditions, and the formation of trade unions, while affirming the rights of property and free enterprise, opposing both socialism and laissez-faire capitalism. He influenced Mariology of the Catholic Church and promoted both the rosary and the scapular. Leo XIII issued a record of eleven papal encyclicals on the rosary earning him the title as the "Rosary Pope". In addition, he approved two new Marian scapulars and was the first pope to fully embrace the concept of Mary as Mediatrix. He was the first pope to have never held any control over the Papal States, after they had been dissolved by 1870.