Metaphors have defined the relationship of a bishop and his diocese since Apostolic times. From the earliest church a bishop was the head of a community, the pastor, the shepherd who cared for his flock. His relationship to that community was based on the recognition that his leadership was personal, caring, and mutual. The shepherd needs flock; the flock needs a shepherd. The bishop was the pastor of his community, the shepherd of the flock who defended them from the wolves of the community and from the dangers of the outside world. His relationship to his church was matrimonial — he was married to his church. This metaphor emphasized the bishop’s commitment to his church and his life-long obligation to it. The bishop, his church, and his flock were also part of a larger institution, the congregratioidelium, the ecclesia Catholica, and the ecclesia universalis. In large part the constitutional position of the bishop in his diocese is the story of the clash of these metaphors.
Kenneth Pennington, Bishops and their Dioceses, 5 FOLIA CANONICA 7 (2002).