It is a Benedictine foundation dedicated to Saint-Sauveur. It was founded in 804 by Guilhem of Orange, Duke of Aquitaine and second Count of Toulouse, a member of Charlemagne's court, later known as Saint Guilhem.
As the medieval pilgrimage route to the shrine of Saint James of Compostella in Spain developed in the 10th century, the monastery of Saint-Guilhem-le-Desert became a staging point on one of the four main routes through Europe leading to it. Like all such staging points it benefited financially from its more than usually gullible pilgrim visitors. By the middle of the 11th century the monks were rich enough to rebuild their monastery on a larger scale in the latest Romanesque style. The present abbey church dates from this period.
By the twelfth century, the abbey had been renamed in honour of its founder. And as the site in the Gellone Valley had been selected because it was a virtual desert, we now know it at the Abbey of Saint-Guilhem-le-Désert.
By 1206, a new cloister had been built at Saint-Guilhem incorporating columns and pilasters which are now located in an American museum. Many of them recall classical Roman columns, but they depart from classical models in their variety of design.
During the 14th to 16th centuries, progressively declined. Under the 'commende' system the abbot was nominated by the king, who selected from among the members of the high clergy (rather than being elected by the monks of the community). The system inevitably led to abuse and for centuries successive Abbots from aristocratic families accumulated titles and neglected their monastic duties.
Like other French religious buildings, Saint-Guilhem suffered in the Wars of Religion during and after the Reformation. In 1569 the Abbey was pillaged by Protestants and sculptures were damaged. Furniture and fittings were sold off to pay for repairs, and for a garrison to protect the Abbey. By 1670 the monastery was in a state of advanced decay. The monks called upon the congregation of Saint-Maur to undertake repair work to save the buildings from ruin and re-establish the monastic life.
The abbey declined in the 18th century. In 1783, it was attached to the bishopric of Lodeve, losing its independence. Monks from Saint-Maur occupied the monastery until the French Revolution, by which time the community had been reduced to six monks. It was suppressed in 1790 during the French Revolution, and the buildings sold ominously to a stonemason. The abbey church escaped vandalism as it became a parish church, but the rest was vandalised. Various businesses were established in the cloister, including a spinning business and a tannery. Private houses were established in the buildings around the cloister and the cloister itself which was used as a stone quarry.
Fragments of the abbey may be found all over the region, and even much further away. You can see some of those columns of the cloister dating from before 1206 in the Cloisters museum, north of New York (part of New York's Metropolitan Museum of Art). It is difficult to know who best deserves the title of Most Cretinous Philistine - the people who sold them, those who bought them, or those who now decline to return them.
The cumulative damage of these various acts of vandalism was so severe that it is now impossible to determine the number and sequence of its columns - or even the dimensions of the cloister.
In 1840, the abbey was taken in hand by the Monuments Historiques. Restoration since 1960 has tried to restore the original aspect of the building. A new cloister has been built. Since the end of the 1970s, a community of monks from Carmel Saint Joseph has made the abbey their home.
The abbey is one of several World Heritage sites in the Languedoc. In 1987, the Abbey of Gellone was classed as a French Historical Monument. On the 5 December, 1998, it was classified as a World Heritage site by UNESCO as part of the "Paths of Saint James" - the pilgrimage routes of St-Jacques de Compostela
Here is an extract from the Met Museum's web page on the Saint-Guilhem-le-Désert's cloister:
By 1206 a new, two-story cloister had been built at Saint-Guilhem, incorporating the columns and pilasters from the upper gallery seen here. Most of these columns are medieval versions of the classical Corinthian column, based on the spiny leaf of the acanthus. This floral ornamentation is treated in a variety of ways. Naturalistic acanthus, with clustered blossoms and precise detailing, is juxtaposed with decoration in low, flat relief, swirling vine forms, and even the conventionalized bark of palm trees. Among the most beautiful capitals are those embellished by drill holes, sometimes in an intricate honeycomb pattern. Like the adaptation of the acanthus-leaf decoration, this prolific use of the drill must have been inspired by the remains of Roman sculpture readily available in southern France at the time. The drilled dark areas contrast with the cream-colored limestone and give the foliage a crisp lacy look that is elegant and sophisticated. Like other French monasteries, Saint-Guilhem suffered greatly in the religious wars following the Reformation and during the French Revolution, when it was sold to a stonemason. The damages were so severe that there is now no way of determining the original dimensions of the cloister or the number and sequence of its columns. Those collected here served in the nineteenth century as grape-arbor supports and ornaments in the garden of a justice of the peace in nearby Aniane. They were purchased by the American sculptor George Grey Barnard before the First World War and brought to this country.