Herford Abbey was the oldest women's religious house in the Duchy of Saxony. It was founded as a house of secular canonesses in 789, but moved later to the present site. The city of Herford grew up on this site around the abbey. The abbey was dedicated in 832 and was elevated to the status of a Reichsabtei ('Imperial abbey') under Emperor Louis the Pious (d. 840).
Between 919 and 924 Herford was destroyed by Hungarians but was rebuilt by 927. In 1147 the abbey, which by this time had almost 850 estates and farms, was granted Imperial immediacy. This made it an independent territory within the Holy Roman Empire which lasted until 1803.
In 1533, during the Reformation, Herford Abbey became Lutheran, under the Electors of Brandenburg. From 1649 for over a century the abbesses were all Calvinist but that did not alter the Lutheran character of the principality.
In 1802 the abbey was dissolved in the course of secularisation. In 1804 it was turned into a collegiate foundation for men, and in 1810 finally suppressed. The former abbey church remains in use as Herford Minster (Herforder Münster). The church is a late Romanesque hall church, built about 1220-1250. It is one of the earliest hall churches in Germany.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.