From the Youtube post:
LibriVox recording of The Great Encyclical Letters of Pope Leo XIII by Pope Leo XIII.
Read in English by Maria Therese
Pope Leo XIII (2 March 1810 – 20 July 1903), born Vincenzo Gioacchino Raffaele Luigi Pecci to an Italian comital family, reigned from 20 February 1878 to his death in 1903. He was the oldest pope (reigning until the age of 93), and had the third longest pontificate, behind that of Pius IX (his immediate predecessor) and John Paul II. He is the most recent pontiff to date to take the pontifical name of “Leo” upon being elected to the pontificate.
He is well known for his intellectualism, the development of social teachings with his famous papal encyclical Rerum novarum and his attempts to define the position of the Catholic Church with regard to modern thinking. He influenced Roman Catholic Mariology and promoted both the rosary and the scapular. He issued a record eleven encyclicals on the rosary earning the moniker the “Rosary Pope”, 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 never have held any control over the Papal States, after they were dissolved by 1870.
Leo XIII died on July 20, 1903 at the age of 93 and was briefly buried in the grottos of Saint Peter’s Basilica before his remains were later transferred to the Basilica of Saint John Lateran.
(From Wikipedia, the free encyclopedia)