Christian Saints

St. Bernard (c.1090-1153) with a group of monks founded the monastery of Clairvaux, which he directed until his death. He played an essential part in developing the cult of the Virgin, toward whom his devotion was particularly strong.
A reforming prelate, a theologian, and author of numerous books, an abbot who rejected both wealth and images, St. Bernard is the most important ecclesiastical figure of the 12th century. His authority was recognized in all Christendom, and he was very often an arbiter between opposing faction in their disputes.
In fine art he is depicted in a white habit; some other attributes, illustrating different episodes of his life, such as a white dog, a chained demon, a book, a mitre on the ground, a beehive or a swam of bees can also be present.
St. Bernard's cult began unofficially during his lifetime. He was formally canonized in 1174 and nominated a Doctor of the Church in 1830.
Feast day: 20 August.

See: Fra Bartolommeo The Vision of St. Bernard.
Filippino Lippi The Apparition of the Virgin to St. Bernard, Madonna and Child Enthroned with St. John the Baptist, St. Victor, St. Bernard and St. Zenobius ("Altarpiece of the Otto di Pratica").
Fra Filippo Lippi The Adoration, with the Infant Baptist and St. Bernard.
Pietro Perugino The Vision of St. Bernard.

Recommended reading:
A Retreat With Benedict and Bernard: Seeking God Alone-- Together (Retreat With-- Series) by Linus Mundy. St Anthony Messenger Press, 1998.
Bernard of Clairvaux (Great Medieval Thinkers) by Gillian R. Evans. Oxford University Press, 2000.
Bernard of Clairvaux: Essential Writings by Dennis E. Tamburello, John Farina. Crossroad/Herder & Herder, 2000.
Bernard of Clairvaux: Selected Works (Classics of Western Spirituality) by G. R. Evans (Translator), Ewert Cousins (Designer), Bernard of Clairvaux. Paulist Press, 1988.
Your Saint Bernard by Marian J. Sharp. Denlinger's Publishers, Ltd., 1978.