The abbey was established in Wienhausen, 15 kilometers (9 miles) from the town of Celle, on the bank of the Aller, in or about 1230 by Agnes von Landsberg, daughter-in-law of Henry the Lion, Duke of Saxony and Bavaria. According to the Wienhausen town chronicle, this was the relocation of a monastic foundation made 10 years previously on a site at Nienhagen several kilometers away, which was moved because it had been built on marshland.