Cluny Abbey (or Cluni, or Clugny, French pronunciation: [klyni]) is a former Benedictine monastery in Cluny, Saône-et-Loire, France. It was dedicated to St Peter. The abbey was constructed in the Romanesque architectural style, with three churches built in succession from the 4th to the early 12th centuries. The earliest basilica was the world's largest church until the St. Peter's Basilica construction began in Rome.
Cluny was founded by William I, Duke of Aquitaine in 910. He nominated Berno as the first Abbot of Cluny, subject only to Pope Sergius III. The abbey was notable for its stricter adherence to the Rule of St. Benedict, whereby Cluny became acknowledged as the leader of western monasticism. The establishment of the Benedictine Order was a keystone to the stability of European society that was achieved in the 11th century. In 1790 during the French Revolution, the abbey was sacked and mostly destroyed, with only a small part of the Abbey surviving.
Starting around 1334, the Abbots of Cluny maintained a townhouse in Paris known as the Hôtel de Cluny, which has been a public museum since 1843. Apart from the name, it no longer possesses anything originally connected with Cluny.
In 910, William I, Duke of Aquitaine "the Pious", and Count of Auvergne, founded the Benedictine Abbey of Cluny on a modest scale, as the motherhouse of the Congregation of Cluny. The deed of gift included vineyards, fields, meadows, woods, waters, mills, serfs, cultivated and uncultivated lands. Hospitality was to be given to the poor, strangers, and pilgrims. It was stipulated that the monastery would be free from local authorities, lay or ecclesiastical, and subject only to the Pope, with the proviso that even he could not seize the property, divide or give it to someone else or appoint an abbot without the consent of the monks. William placed Cluny under the protection of saints Peter and Paul, with a powerful curse on anyone who should violate the charter. With the Pope across the Alps in Italy, this meant the monastery was essentially independent.