A few dates help us to understand the history of the Abbey. It was founded in 1168 by Hugues WAC, a descendant of one of William’s companions who conquered England a century earlier. The monks, Benedictines, came from Hambye Abbey in the Manche, near La Haye Pesnel, itself founded in 1145.
It was in the 13th century that it experienced its greatest expansion. But it seems that the religious community was never important: about twenty monks at that time, to which were added the “lay brothers” essential to the construction of the conventual buildings, to the exploitation of the lands, to the reception of the pilgrims on their way to Santiago de Compostela.
In 1526, it fell into “commendation” and the decline began, the successive abbots often finding , at the abbey, the opportunity to enrich themselves at the expense of the community for which they were responsible. In 1640, the nave of the church threatened to collapse, and Jean V de Tulles, bishop of Orange, twenty-seventh abbot of Longues, decided to abandon it: he had a wall built at the junction of the nave and the choir, leaving only the choir available to the monks. His coat of arms, incorporated into this wall, is still visible there.
In 1781, there is a decree from Monseigneur de CHEYLUS, bishop of Bayeux, to do away with the abbey. In 1793, the land was sold as national property. Since then, the abbey has changed hands twelve times. In the XIXth century, the buildings were progressively degraded and used as a stone quarry to build various houses in the village. The ruins of the church were classified as Historical Monuments in 1915. The other buildings are listed in the Supplementary Inventory of Historical Monuments.