According to tradition, the monastery was founded around 770 on an island in the Federsee by the Frankish Count Warin, his wife Adelindis von Buchau (still commemorated in the local Adelindisfest).

The abbey was put on a secure financial footing by Louis the Pious, who in 819 granted the nuns property in Mengen.

In 857, Louis the German declared it a private religious house of the Carolingian Imperial family, appointed as abbess his daughter Irmingard (died 16 July 866), and granted the abbey lands at Saulgau.

In 1347, Buchau Abbey gained Imperial immediacy and the abbess was raised to the rank of Princess-Abbess.

In 1415, the abbey became a secular foundation and from then on the congregation was to be composed of an abbess, twelve canonesses choral (choir women or Chorfrauen) and two chaplains.