Bernard of Clairvaux was a Burgundian nobleman who entered Cîteaux in 1112 and founded Clairvaux, becoming the most influential churchman of the twelfth century and a Doctor of the Church. His sermons on the Song of Songs, his treatises on grace and the love of God, and his preaching of the Second Crusade made him the conscience of his age and the last of the Fathers in the West.