E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The Count de Grammonts short memory. When the Count left England he was followed by the brothers of La Belle Hamilton, who, with drawn swords, asked him if he had not forgotten something. True, true, said the Count; I promised to marry your sister, and instantly went back to repair the lapse by making the young lady Countess of Grammont.