The Presbyterian eldership traces its modern form to John Calvin's reforms in sixteenth-century Geneva, where a consistory of ministers and lay elders together exercised oversight of the city's moral and religious life, a structure Calvin and his associates, including his student John Knox, who carried the model to Scotland, argued more faithfully reflected the New Testament church's own leadership pattern of a plurality of elders than either the Roman Catholic episcopal hierarchy or the more radical congregational independence some other Reformation movements adopted. Knox's Scottish Reformation established Presbyterian polity as the governing structure of the Church of Scotland, from which it spread through Scottish and later broader British emigration to North America, where Presbyterian denominations became a major and doctrinally influential branch of American Protestantism, particularly through institutions such as Princeton Theological Seminary.
The session, a congregation's own body of teaching and ruling elders, sits within a wider Presbyterian governance structure of ascending representative courts, the presbytery, grouping several congregations' sessions, and, above it, a synod or general assembly governing the denomination as a whole, a layered representative system Presbyterians present as a deliberate middle path between the concentrated authority of episcopal church government and the fully autonomous local authority of congregational polity.