The original site was a Benedictine monastery, founded in about 762 by the brothers Adalbert and Otker, traditionally supposed to be members of the Huosi, an ancient Bavarian noble family. The monastery was dedicated to Saints Arsatius, whose relics were here, and Quirinus, whose relics were at Tegernsee Abbey, founded by the same brothers, to which Ilmmünster was affiliated.
A collegiate foundation was also set up here in 1060. In 1493, the monastery was transferred to the Frauenstift in Munich, leaving the site for the Kollegiatstift. The property and assets were sold off in 1802 during secularisation, but the impressive church remains.
- (in German) Klöster in Bayern