Cluny was founded by Duke William I 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 surviving.