The municipal protestant church (evangelische Stadtkirche) was built according to plans by the famous Karlsruhe architect Friedrich Weinbrenner as the cathedral church of Baden following instructions from Grand Duke Karl Friedrich.
The foundation stone was laid on 8 June 1807. The church was consecrated at Whitsun 1816. Weinbrenner modelled the church on a Greek temple. A bell tower isn't really appropriate for a temple but the Grand Duke's wishes held sway so Weinbrenner set it as far away from the façade as possible. The gable of the porch is supported by six high Corinthian columns. A gilded Angel of Peace adorns the top of the spire.
The municipal protestant church was preceded by the "Konkordienkirche" or "Kirche der Eintracht" built on the market square in 1721 and in which the city's founder, Karl Wilhelm (1709 - 1738), was buried. Weinbrenner built the pyramid over the Grand Duke's crypt in 1825.
The church was destroyed by air raids in 1944. When it was rebuilt in 1958, its interior was redesigned: brighter, wider, opening the end wall in which the altar now stands, no pictures or statues, lightweight pillars instead of the original Corinthian columns. Strip lighting along the longitudinal walls draws attention upwards. The ceiling is arched instead of the original coffered construction. The materials are open to view in the typically 1950s style: stone, concrete, wood, steel, leather.
Beneath the nave of the church is the former crypt of the Grand Duke's family. It contains Weinbrenner's sarcophagus.
The reconstructed church has seating for 1320 people. The altar and pulpit, like the floor, are made of black marble. The biblical watchword for the year is displayed on the pulpit. The font and altar cross are works of the sculptor Otto Herbert Hajek and the windows in the gable wall were created by Georg Meistermann. Both artists held professorships at the art academy in later years. The municipal protestant church had an organ made by the great organ builder Silbermann from the Alsace region of France until 1944. The new instrument is an organ made by the company Steinmeyer in Oettingen. It has 73 stops on four keyboards and pedals with approximately 4500 pipes. The organ was completely overhauled and fitted with an electronic stop-combination capture system in 2005. The Alsatian Rémy-Mahler organ in the front section of the church was officially inaugurated as a choir organ in January 2005. It has 24 stops on three keyboards and pedals and comes close to the tone of the old Silbermann organ.