Saint Bernard of Clairvaux (1090-1153) was the great Cistercian abbot, mystic, and Doctor of the Church known as the 'Mellifluous Doctor.' He founded the monastery of Clairvaux, preached the Second Crusade, defended the Church against the errors of his day, and wrote luminous works on the love of God and the Blessed Virgin Mary. He was canonized in 1174.