This book assesses episcopal cooperation as envisioned by the third-century bishop Cyprian of Carthage. It outlines and assesses the interactions between local bishops, provincial groups of bishops, and the worldwide college. Assessing these interactions sheds light on the relationship between Cyprian's strong sense of local autonomy and the reality that each bishop was responsible to the world-wide college. Episcopal consensus was the sine qua non, for Cyprian, for a major issue of faith or practice to become one that defined membership in the college and, ultimately, the Church. The book brings this assessment into a modern scholarly debate by concluding with an evaluation of the ecclesiology of the Orthodox scholar Nicolas Afanasiev and his critiques of Cyprian. Afanasiev lamented Cyprian as the father of universal ecclesiology and claimed that Cyprian's college wielded authority above that of the local bishop. This book argues that Afanasiev fundamentally misconstrued Cyprian's understanding of collegiality. It is shown that, for Cyprian, collegiality was the framework for the common ministry of the bishops and did not infringe on the sovereignty of the local bishop. Rather, it was the college's collective duty to define the boundaries of acceptable Christian belief and practice.