The Protestant Church of Peace () is situated in the Marly Gardens on the Green Fence (Am Grünen Gitter) in the palace grounds of Sanssouci Park in Potsdam, Germany. The church was built according to the wishes and with the close involvement of the artistically gifted King Frederick William IV and designed by the court architect, Ludwig Persius. After Persius' death in 1845, the architect Friedrich August Stüler was charged with continuing his work. Building included work by Ferdinand von Arnim and also. The church is located in the area covered by the UNESCO World Heritage Site Palaces and Parks of Potsdam and Berlin.
The cornerstone of the churchhouse was laid on 14 April 1845. The building was dedicated on 24 September 1848, though construction continued until 1854. The structure resembles a High Medieval Italian monastery.
The Church of Peace
Frederick William himself made the original sketches on which the design was to be based. He gave his court architect Ludwig Persius two main instructions: The church was to derive in form and size from the early Christian Basilica di San Clemente in Rome. And it had to accommodate the apse mosaic from the church San Cipriano on the island of Murano in the Venetian Lagoon, which Frederick William had purchased in 1834 when that church was scheduled for demolition. A popular etching of the early Christian version of the Basilica di San Clemente in Rome made by and Johann Michael Knapp probably inspired the design of the Potsdam church.
Under Frederick William, the church served as the chapel royal and as church for the parish of Brandenburger Vorstadt (a part of Potsdam).
The church is a columned basilica with three naves and no transept, with a free-standing belltower. The 13.5 m high central nave overlaps the side aisles, which are half as wide. An arcade of central arches mark the crossing point.
The religious Frederick William IV desired a flat coffered ceiling on the inside, with gold stars on a blue base painted on the panels.
The king saw the design of early Christian sacred buildings, converted from market and court halls, as particularly appropriate. He was trying to establish a reconciliation between the Protestant majority of the original Prussian state and the Catholics of the more recently acquired lands, notably in the Rhineland Province. Since he associated Gothic architecture with the Catholic faith, he was looking for an alternative design vocabulary for the Prussian-Protestant church. Skipping Martin Luther, he went back to early Christianity as an inspiration. However, he did not distinguish too finely between early Christian and High Medieval architecture - as long as it was Romanesque.
An original Venetian mosaic from the early 13th century decorates the church's apse. While he was crown prince Frederick William had it bought at auction for 385 thalers and brought to Potsdam by boat. The mosaic shows the enthroned Christ with the Book of Life, the right hand upheld in blessing. At each side stand Mary and John the Baptist. Next to them stand the apostle Peter and Saint Cyprian, martyred by beheading in 258 and patron saint of the church San Cipriano, wearing chasubles. As an allegory for the Holy Spirit, a dove decorates the vertex of the hemisphere. Over the heads of the archangels Raphael and Michael a lamb shines as a symbol of Christ. On the semicircle of the apse a Latin inscript reads, according to Martin Luther's translation: "Lord, I have love for the site of your house and the place where your glory resides".
The altar canopy, which rests on four dark green columns, was created from Siberian jasper (semi-precious stones) and was a gift from Tsar Nicholas I of Russia, the king's brother in law. It was installed in the Church of Peace in 1842.
In the right-hand aisle lies the former baptistery. The six-sided baptismal stone was relocated in 1965.
The counterpart to the baptistery is the sacristy in the left-hand aisle. After the death of Frederick William IV it was used temporarily as a mausoleum for him and for other deceased members of the House of Hohenzollern. The son of Emperor Friedrich III and his wife Empress Victoria, as well as the Princes Sigismund and Waldemar, were entombed here until 1892. In 1920 the youngest son of Wilhelm II, the last Emperor of Germany, was interred in the sacristy. After 1931 he was moved to the Antique Temple.