The landed wealth of the Church alone sufficed to make it a power of the highest rank in the feudal system of the Middle Ages, in which all power finally rested on the possession of the land. Bishops and abbots became feudal dignitaries, sometimes almost sovereign princes in their own domains, and always with a potent voice in the government of their nations.
p. 144 - Christianity and the Social Crisis (1907) - Ch.4 Why Has Christianity Never Undertaken the Work of Social Reconstruction?