It was originally built in 1134 on land presented as a gift to the Cistercians by
Henry I of England. The stagnant water of the drainage lake, dug out by the monks to dry up the marshy land around the quick-running Fouillebroc stream, was called the "dead pond" - in
French "morte mare" - and gave the monastery its name. The monks constructed what was then one of the largest Cistercian monastery in the world. Over the centuries, the abbey fell into decline and disrepair. It was rebuilt in the 17th century, but the decline was irreversible and by 1790, when it was dissolved in the course of the
French Revolution, only five monks remained. ==Buildings==