Old Lutherans are German Lutherans in Prussia and Silesia who refused to join the Prussian Union of churches in the 1830s and 1840s. Prussia's king Frederick William III was determined to unify the Protestant churches, to homogenize their liturgy, organization and even their architecture. In a series of proclamations over several years the Church of the Prussian Union was formed, bringing together the majority group of Lutherans, the minority of Reformed. The main effect was that the government of Prussia had full control over church affairs, with the king recognized as the leading bishop.
Attempted suppression of the Old Lutherans led many to emigrate to Australia, Canada, and the United States, resulting in the creation of significant Lutheran denominations in those countries.
The legacy of Old Lutherans also survives in the Independent Evangelical Lutheran Church in modern Germany.
In 1799 King Frederick William III of Prussia issued a decree for a new common liturgical Agenda (service book) to be published, for use in both the Lutheran and Reformed congregations. To accomplish this, a commission to prepare a common agenda was formed.
After more than 20 years of effort, a common liturgical agenda was finally published in 1821. The agenda was not well received by many Lutherans, as it was seen to compromise in the wording of the Words of Institution, to the point where the Real Presence of Christ in the Eucharist was not proclaimed.
The Protestant congregations were directed in 1822 to use only the newly formulated agenda for worship. This met with strong objections and non-compliance from Lutheran pastors around Prussia.
The liturgical agenda was subsequently modified to appease many of the objections of the dissenting Lutherans, and in 1830 Frederick William ordered all Protestant congregations in Prussia to celebrate the Lord's Supper using the new agenda.