1891: Leo XIII’s encyclical Rerum Novarum (On the Condition of the Working Classes)
Rerum Novarum was a groundbreaking encyclical from Pope Leo Xlll in 1891 that laid the foundation for modern Catholic Social Teaching. It directly took up the issue of the dignity and rights of workers in a rapidly changing world where industrialisation had created an ever widening gap between the materially rich and the working poor.