The Fraumünster abbey ([Our] Lady Minster) in Zurich was founded in 853 by Louis the German for his daughter Hildegard. He endowed the Benedictine convent with the lands of Zurich, Uri, and the Albis forest, and granted the convent immunity, placing it under his direct authority. In 1045, King Henry III granted the convent the right to hold markets, collect tolls, and mint coins, and thus effectively made the abbess the ruler of the city. Emperor Frederick II granted the abbey Reichsunmittelbarkeit in 1218, thus making it territorially independent of all authority save that of the Emperor himself, and increasing the political power of the abbess.
The abbess assigned the mayor, and she frequently delegated the minting of coins to citizens of the city. However, the political power of the convent slowly waned in the fourteenth century, beginning with the establishment of the Zunftordnung (guild laws) in 1336 by Rudolf Brun, who also became the first independent mayor, i.e. not assigned by the abbess. The abbey was dissolved on 30 November 1524 in the course of the reformation of Huldrych Zwingli. The monastery buildings were destroyed in 1898 to make room for the new Stadthaus.
The church building today serves as the parish church for one of the city's 34 reformed parishes. Münsterhof, the town square in front of Fraumünster, is named after the former abbey. The choir of the abbey includes 5 large stained glass windows designed by artist Marc Chagall and installed in 1970. Each of the 5 has a dominant color and depicts a Christian story. From left (northern wall) to right, the 5 works are: Equally impressive is the 9m tall stained glass of the North transept, created by Augusto Giacometti in 1940.