The Industrial Revolution brought many concerns about the deteriorating working and living conditions of urban workers. Influenced by the German Bishop Wilhelm Emmanuel Freiherr von Ketteler, in 1891 Pope Leo XIII published the encyclical Rerum novarum, which set in context Catholic social teaching in terms that rejected socialism but advocated the regulation of working conditions. Rerum novarum argued for the establishment of a living wage and the right of workers to form trade unions.[202]