Lithuanian Evangelical Reformed Church
The church was founded on December 14, 1557, during the Synod of Vilnius. The General synod met annually in Lithuania from that date. Started with 2 later grew to six districts Synods. The church's Latin name is the " Unitas Lithuaniae " shortly UL. It sent its representatives to the Polish-Lithuanian Commonwealth. But the UL was an independent denomination. The parish network covered all parts of the Grand Duchy of Lithuania. The first superintendent was Szymon Zacjusz. In 1565, the anti-Trinitarian Lithuanian brotherhood separated from the Reformed church.
Parishes were in Vilnius, Biržai, Kėdainiai, Slutsk, Dzyarzhynsk (Koydanava), Zabłudów and later in Izabelin (Belarusian: Ізабэлін). Before World War II, the church had 10,000 believers. Now has 7,000 in 14 congregations. In 1922 the denomination become a member of the World Communion of Reformed Churches.
The church adheres to the Sandomierz Confession (Confessija Sandomierska) (1570), Second Helvetic Confession (1562), Heidelberg Catechism (1563). These are in Lithuanian and Polish language. The Sandomierz Confession was based on the Second Helvetic Confession and adopted by the Polish-Lithuanian General Synod, and was approved later the Lithuanian Reformed Church. The Great Gdansk Agenda (1637) is a liturgical book approved and adopted by the Unitas Lithuaniae.
The church is a member of the World Communion of Reformed Churches and has fraternal relationships with the Reformed Church in Hungary, the Church of Lippe, Mission Covenant Church of Sweden, Presbyterian Church (USA), Evangelical Church in Liechtenstein. Denominational member of the World Reformed Fellowship.