Papst Leo XIII.
Pope, 1810-1903
"Pope Leo XIII, born Vincenzo Gioacchino Raffaele Luigi Pecci, was the chief pastor of the Catholic Church from 20 February 1878 to his death. He is 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"", Pope Leo 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."
Source: Wikipedia