Stephen was born of Anglo-Saxon parents at Sherborne in Dorset, educated at the Benedictine abbey there, and after the Norman Conquest left England for Scotland, then for the schools of Paris, and finally for Italy. Returning home to Burgundy with a fellow scholar he stopped at Molesme, where he became a monk under Robert and was among the twenty-one who left with Robert and Alberic in 1098 to found Cîteaux.
After Alberic's death in 1109 Stephen was elected third abbot of Cîteaux. He governed for twenty-five years and is the principal architect of the Cistercian Order: he composed (or substantially compiled) the Carta Caritatis — the 'Charter of Charity' — the constitution that bound every Cistercian house to the original observance and to fraternal mutual visitation, distinguishing the Cistercians sharply from the looser Cluniac confederation.
He received Bernard of Clairvaux with his thirty companions in 1112 and within three years was sending Bernard out to found Clairvaux. By Stephen's death in 1134 there were already 75 Cistercian houses across Europe. His Cîteaux Bible — a four-volume corrected text he commissioned and helped collate — survives at Dijon as one of the great manuscripts of the twelfth century.