Classicly

The idea of this tale was taken from The Mariners’ Chronicle, compiled by a person named Scott early in the last century—a curious book of narratives of maritime adventures, with exceedingly quaint illustrations.  Nothing has ever shown me more plainly that truth is stranger than fiction, for all that is most improbable here is the actual fact.

The Comte de Bourke was really an Irish Jacobite, naturalised in France, and married to the daughter of the Marquis de Varennes, as well as in high favour with the Marshal Duke of Berwick.