E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The 15th Hussars, now the 15th [Kings] Hussars, previously called the 15th, or kings own royal light dragoon guards. In 1759 Lieutenant-Colonel Eliott enlisted a large number of tailors on strike into a cavalry regiment modelled after the Prussian hussars. This regiment so highly distinguished themselves, that George III. granted them the honour of being called the kings royal.