Bearded Master (Magister barbatus). So Persius styled Socrates,
under the notion that the beard is the symbol of wisdom.
(Bearded). Constantine IV., Emperor of Rome (648, 668-685).
Geoffrey the Crusader, and Bouchard of the house of
Baldwin IV., Earl of Flanders. (1160-1186.)
John the Bearded.
Johann Mayo, the German painter, whose beard touched the ground
when he stood upright.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894