The Kaufmannskirche St. Gregor (Merchant's Church St Gregory) is a 14th-century Gothic parish church at Anger Square. It is one of the largest and most important original parish churches in Erfurt. The parents of Johann Sebastian Bach, Johann Ambrosius Bach and Maria Elisabeth Lämmerhirt married here in 1668.
The former Romanesque building (11th century) on the site was burnt down in 1291. The consecration of the Gothic basilica with twin choir towers took place in 1368. The altar (1625), pulpit (1598), baptismal font (1608), epitaphs (1584/85/90) are works of the Thuringian Late Renaissance and forms of Luther iconography of Erfurt sculptors and stone masons Hans Friedemann, the Elder and Younger. Martin Luther preached here on 22th October 1522.
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.