E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A boy kept to be whipped when a prince deserved chastisement. Mungo Murray stood for Charles I., Barnaby Fitzpatrick for Edward VI. (Fuller: Church History, ii. 342.) DOssat and Du Perron, afterwards cardinals, were whipped by Clement VIII. for Henri IV. of France. Also called a whip-boy.