In the European Middle Ages, the two settlements named Unterbollingen and Oberbollingen are mentioned as part of the later Herrschaft Rapperswil of the Counts of Rapperswil. The earliest document sealed at the Rapperswil Castle was related to the donation of the church of Unterbollingen to the Rüti Abbey, and also mentions among others a civitas of the town of Rapperswil as witnesses of Count Rudolf von Rapperswil in 1229. On the peninsula at Oberbollingen, a St. Nicholas Chapel is mentioned, where around 1229 a small Cistercian nunnery, later Premonstratensian convent associated with the Rüti Abbey was established by the Counts of Rapperswil; in 1267 it was united with the nearby MariazellWurmsbach Abbey. In 1519 a new church in honor of St. Pancras was inaugurated in Unterbollingen. After the Reformation in Zürich the church was acquired by the city of Rapperswil to be united with the Heiliggeistspital, but since 1871 it is a parish church for its own.