St. Bernard of Clairvaux, our patron saint
St. Bernard of Clairvaux is arguably the most important figure in European history in the twelfth century. As the founder of the Cistercians, he spear-headed a reform of the monastic movement that had great impact on the Church as a whole, served as an advisor to popes and kings, and - through his connection with the Crusades - even had an impact on the larger course of European history. Although his writings are not as accessible today as those of St. Thomas Aquinas (who lived a century later), he is revered as a Doctor of the Church, a great monk and mystic who was at the same time a man of public affairs.
You can read about his life in the New Advent Catholic Encyclopedia online, here.