Leo XIII, (Vincenzo Gioacchino Pecci) (1810–1903)

Pope from 1878. After a successful career as a papal diplomat, he established good relations between the papacy and European powers, the USA, and Japan. He remained intransigent in negotiations with the Italian government over the status of Rome, insisting that he keep control over part of it.

He was the first pope to emphasize the duty of the church in matters of social justice. His encyclical Rerum novarum 1891 pointed out the moral duties of employers towards workers.