Richardis, wife of Charles III (aka "Charles the Fat") and so "Holy Roman Empress", founded the abbey in Andlau ca 880. Later she lived here (as the abbess). She was known for her piety and so she was canonised, when Pope Leo IX visited the abbey in 1049.

The crypt of "Saints-Pierre-et-Paul" is the oldest part of the whole structure. The eastern part of the crypt dates back to 1080/1100, the western, was constructed around 1160.
There is a legend telling that a bear showed Richardis the place, where the abbey should be built. See the statue of the bear - and in front under the small wooden cover is the exactly place, that the bear had choosen.