Pope Leo XIII: His Life and Work by Julien de Narfon (1899) provides a detailed biography of Pope Leo XIII, covering his early life, education, and pontificate. It highlights his important contributions, including the social encyclical Rerum Novarum, his efforts to modernize the Church, and his international diplomacy. It highlights Leo XIII as one of the most influential church leaders, particularly in bridging Church teaching with the challenges of the modern age. It is considered a classic work essential for understanding the historical context of Leo XIII's papacy in the late 19th century.