Thanks for clearing that up, Caroline - splendid research.

A thought has occured to me that I may have been misled in thinking of a French rather than an Irish origin for the name Darcy because of the tendency to spell it with an apostrophe (D'Arcy). Could this be a deliberate attempt by some early Darcys at making it look aristocratic French and therefore posh? It's not so much a French origin, as a 'de' in the name.

People whose name is Death have been known to change it to De Ath or D'Eath (though perhaps they have other reasns for wanting to disguise the name). Hardy makes a point of this sort of thing in "Tess of the D'Urbervilles" - or should that be "Tess of the Darbyfields"?

In France in the Revolution the reverse happened, as aristocratic ancestry was something of a liability. The revolutionary Danton, for example, was originally D'Anton, and Maximilien de Robespierre quickly disposed of the 'de'.

PS: re Irish Wentworths. In 'Persuasion', it is established at the start of the novel that they are "no connection with the Strafford family" (which would be the Fitzwilliams that Caroline refers to). Lady Dalrymple later admires Captain Wentworth and says "Irish, I dare say?" which Sir Walter denies.