Rapperswil has been an independent parish since 1253. Previously, the church was under the authority of the Pfäfers monastery near Ragaz. The current neo-Gothic church with its mismatched Romanesque-Gothic towers was largely rebuilt after a devastating fire in 1882. The first church in the shadow of the castle was built on behalf of the Count of Rapperswil at the time the town was founded around 1229.
Excavations carried out during the renovation in 1970/71 revealed a Romanesque hall church with a straight choir wall, to which parts of the cemetery were attached. In 1383, the church was extended by 8 metres towards the castle and raised. After 1441, the Romanesque north tower of the hall church was joined by the Gothic south tower, which was slightly larger. The Gothic renovation in 1493-97 (three-sided choir with ribbed vaulting, tracery windows) was made possible by fundraising campaigns in Habsburg cities and a bequest from Countess Gutta von Reinach-Wertheim. The Renaissance wing altars in the side chapels, created after the iconoclastic Reformation in 1531, were spared from the devastating church fire on 30 January 1882, as they had been moved to other chapels during the Baroque period. The church treasure, which was secured in the tower vault, also survived the fire: masterpieces by the Rapperswil goldsmiths Breny, Dietrich, Domeisen, Büssi, Ysenschlegel and others.
(Peter Röllin, Kulturbaukasten Rapperswil-Jona, 36 museums under one roof, pages 48, 49)
