Which monastic order founded in 910 became very influential in the Middle Ages?

The story behind the answer

Founded in 910 at an abbey in Burgundy, this reform movement placed its houses under direct papal protection and followed a rigorous interpretation of the Benedictine Rule. By creating a centralized network of dependent priories led by powerful abbots such as Odo, Odilo, and Hugh, it spread its influence across Europe, shaping church life, politics, and culture.

Its emphasis on elaborate liturgy and continual prayer helped drive the Gregorian Reform and promoted peace initiatives like the Peace and Truce of God. The community’s patronage fueled Romanesque art and architecture—its church, often called Cluny III, was the largest in Christendom before St. Peter’s. Though later eclipsed by more austere movements like the Cistercians, its reach during the High Middle Ages was unmatched.