French Benedictine monk and abbot, monastic reformer, and founder of Cîteaux (Latin Cistercium) Abbey (1098), which developed into the Cistercian Order.

The son of noble parents, Robert entered the Benedictine monastery of Moutier-la-Celle near Troyes as a youth and soon became prior. He later became abbot of Saint-Michel-de-Tonnerre, near Langres, where he attempted reforms with little success. He eventually accepted the request of some hermits to become their leader, and in 1075 they established themselves at Molesme. Their austere life gradually gave way to prosperity and laxity, and in 1098 Robert and about 20 monks withdrew to establish Cîteaux, where they strictly followed St. Benedict's Rule.