Blue Beard, the name of the blood thirsty husband in the familiar tale of "Blue Beard," best described in Perrault's "Tales" (1697). The original of this monstrous personage was a character celebrated in Breton legend, Gilles de Laval, Baron de Retz (1396-1440), famous in the wars of Charles VII. According to tradition he used to entice the children of peasants into his castle, and there sacrifice them to the Devil and practice sorcery with the remains. After 14 years of such a course he grew so bold that his crimes were discovered, and a heap of children's bones found in his castle. He was condemned to death, strangled, and his corpse burned at the stake at Nantes in 1440. Another Breton legend represents de Retz with a red beard about to marry a beautiful girl after having already made away with seven wives. The bride expostulates at the altar. De Retz offers her find clothes, castles, all his possessions, finally his body and soul. "I accept!" shrieks the bride, turning into a blue devil and making a sign which transforms de Retz's beard from red to blue. Henceforth he belonged to Hell, and became the dread of the country round, under the name of Blue Beard.

Entry from Everybody's Cyclopedia, 1912.