E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Les Gueux. The ragamuffins. A nickname assumed by the first revolutionists of Holland in 1665. It arose thus: When the Duchess of Parma made inquiry about them of Count Berlaymont, he told her they were the scum and offscouring of the people (les gueux). This being made public, the party took the name in defiance, and from that moment dressed like beggars, substituted a foxs tail in lieu of a feather, and a wooden platter instead of a brooch. They met at a public-house which had for its sign a cock crowing these words, Vive les Gueux par tout le monde! (See Motley: Dutch Republic, ii. 6.)
The word gueux was, of course, not invented by Berlaymont, but only applied by him to the deputation referred to. In Spain, long before, those who opposed the Inquisition were so called.
N.B. The revolters of Guienne assumed the name of Eaters; those of Normandy Barefoot; those of Beausse and Soulogne Wooden-pattens; and in the French Revolution the most violent were termed Sansculottes.