Presbyterians and Reformed Christians affirm presbyterian church government: rule by presbyters, or elders, acting together in a series of graded assemblies rather than by individual bishops or independent congregations. Each congregation is governed by a body of elders (a session or consistory), and these are bound together in wider courts (presbytery, synod, and general assembly), so that authority is shared and appealable. The pattern is held to reflect the New Testament use of elders and the principle that Christ alone is head of the church, exercised through the collective judgement of ordained office-bearers.
John Knox and his fellow reformers set out the new church's governance in the First Book of Discipline of 1560, establishing kirk sessions, presbyteries, and a general assembly for the newly reformed Church of Scotland; the polity was not settled without conflict, since subsequent Stuart monarchs, James VI and I and Charles I among them, repeatedly tried to impose episcopal government on Scotland against fierce Presbyterian resistance, a struggle that culminated in the Bishops' Wars of 1639-40 and fed directly into the wider British civil wars of the following decade, after which Presbyterian church government was decisively secured as the polity of the national Church of Scotland.