Historically, this has been understood as a succession in office, a succession of valid ordinations, or a succession of the entire college. It is understood as a sign and guarantee that the Church, both local and universal, is in diachronic continuity with the apostles; a necessary but insufficient guarantor thereof. Papal primacy is different though related to apostolic succession as described here. The Roman Catholic Church has traditionally claimed a unique leadership role for the Apostle Peter, believed to have been named by Jesus as head of the Apostles and as a focus of their unity, who became the first Bishop of Rome, and whose successors inherited the role and accordingly became the leaders of the worldwide Church as well. Even so, Roman Catholicism acknowledges the papacy is built on apostolic succession, not the other way around. As such, apostolic succession is a foundational doctrine of authority in the Catholic Church. Peter was succeeded by Linus, Linus by Clement, Clement by Anacletus, Anacletus by Evaristus..."The Roman Catholic position is summarised this way: "The Lord says to Peter: 'I say to you,’ he says, 'that you are Peter, and upon this rock I will build my Church, and the gates of hell will not overcome it ....’ On him [Peter] he builds the Church, and to him he gives the command to feed the sheep, and although he assigns a like power to all the apostles, yet he founded a single chair [cathedra], and he established by his own authority a source and an intrinsic reason for that unity.... If someone [today] does not hold fast to this unity of Peter, can he imagine that he still holds the faith? If he [should] desert the chair of Peter upon whom the Church was built, can he still be confident that he is in the Church?" Roman Catholicism holds that Christ entrusted the Apostles with the leadership of the community of believers, and the obligation to transmit and preserve the "deposit of faith" (the experience of Christ and his teachings contained in the doctrinal "tradition" handed down from the time of the apostles and the written portion, which is Scripture). The apostles then passed on this office and authority by ordaining bishops to follow after them. Roman Catholic theology holds that the apostolic succession effects the power and authority to administer the sacraments except for baptism and matrimony. (Baptism may be administered