Ozment, Steven E. The Age of Reform: 1250-1550 : An Intellectual and Religious History of Late Medieval and Reformation Europe. New Haven, Conn. ; London: Yale University Press, 1980. Kindle Electronic Edition.
Chapter 4, “The Ecclesiopolitical Traditions” pp. 135-181 Part 6, “The Conciliar Movement After Constance” pp. 172-181.
The council of Constance in 1417 passed a decree known as Frequens. “Frequens provided for regular meetings of a general council of the church, thereby establishing the council as a permanent feature of church governance” (Ozment 1980, 172). The plans of these meetings quickly fell apart, with the first one cancelled by the plague, a second adjourned because of a dispute over the legitimacy and ongoing political changes. The council, nevertheless constituted, pursued numerous changes, particularly in the college of cardinals and the papal selection (Ozment 1980, 173). In the 15th century there were several recurring councils which attempted to exert influence over the papacy, deciding what was and was not permissible in a broad spectrum of life (Ozment 1980, 175). Ozment sums up this complex time on p. 178. “Three points of view on the relationship between church and state competed in the later Middle Ages. One strictly subordinated secular to ecclesiastical power and found advocates among popes and their apologists A second was championed by extreme royal publicity, who reversed the papal arguments and subordinated ecclesiastical to secular power and treated the church as a department of state. The third saw church and state as parallel powers and attempted to acknowledge the autonomy of each within its respective sphere.”
Ozment is clear that his synthesis cannot exist without generalization that misses nuance. “The Middle Ages were anything but a period of conformist religion and church domination. Europe was a factious family of nation states, not a harmonious corpus Christianum” (Ozment 1980, 180). There was considerable strife between church and state, as well as within the church and among the states.