The Eastern Churches maintained the idea that every local city-church with its bishop, presbyters, deacons and people celebrating the eucharist constituted the whole church. In this view called eucharistic ecclesiology (or more recently holographic ecclesiology), every bishop is Saint Peter's successor in his church ("the Church"), and the churches form what Eusebius called a common union of churches. This implied that all bishops were ontologically equal, although functionally particular bishops could be granted special privileges by other bishops and serve as metropolitans, archbishops or patriarchs.