E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Catharine of Russia.
A sutler. When Czar Peter wished to marry her, it was needful to make her of noble birth; so a private person was first converted into her brother, and then into a great lord by birth. Hence Catharine, being the sister of a great lord, was made fit to be the wife of the Czar. (De Cusine Russia, chap. iv.)