The Gedächtniskirche der Protestation ('The Memorial Church of the Protestation') was built between 1893 and 1904. It was constructed in memory of the protest that took place at the Diet of Speyer by the Protestant states of the Holy Roman Empire in 1529. The tower is the tallest bell tower in the palatinate with 100 m. Its construction was supposed to be a reminder of the protest action that the imperial evangelical states brought to bear in 1529 at the Reichstag in Speyer. The Luther memorial in the vestibule and the adjacent statues of local Protestant rulers serve as reminders of this event.
During the cultural struggles at the end of the 19th century, relationships between Catholics and Protestants were tense. That had its impact on the construction of the Memorial Church which was, under no circumstances, to be any less assertive than the Cathedral. In any event, the construction was controversial, even for evangelical Christians.
The Protestants collected donations and even gained the support of Kaiser Wilhelm II and his wife, who donated the glass window in the apse. Following the plans of Julius Flügge und Carl Nordmann, the church was built very lavishly out of white-gray Vosges sandstone.
In 1979, the organ was replaced. The current organ comes from the Detlef Kleuker workshop and is, with its 95 registers, the largest organ in southwest Germany and the second largest mechanical organ in the world.
Organ concerts and matinees take place regularly in the Memorial Church.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.