The article studies the ministry of the papacy in relation to the ministry of the episcopate, within the links of affectus collegialis. It comments on the hermaneutic of Vatican I and the ecclesiology of Vatican II. This ecclesiology is permeated with a sacramental dimension, where the Petrine ministry is understood within the sacrament of the episcopal order, as a particular title, within the sphere of sollicitudo omnium ecclesiarum and of conspiratio in unum. The perspective begins from the apostolic college instituted by Christ and continued in their successors, united in the framework of the universal Church. It considers the specificity of the Petrine ministry, along with the koinonia of the Churches, linking the universal Church and the particular Church, and the Bishop of Rome with the episcopal college. It considers the unity of the episcopate and the episcopal character of the primacy. There is a Eucharistic foundation for this in the Church, since the Eucharist is celebrated in a particular community and makes present the entire Church. The ministry of communion sustained by the Holy Spirit, and the sollicitudo omnium ecclesiarum is the province of all the bishops, and it is the task of Peter to promote the visible communion of believers within and at the service of the episcopal mission, as centrum unitatis. The primacy includes the power to lead in the areas of faith and of discipline. The primacy is related to the synodal dynamism, which implies the involvement of all in the faith and lavishes help for decisions. The article concludes with a reference to Orthodox theology.