Spanish Coin is one of my favourite regencies. It has stood the test of time and re-reads. From its clever title (appropriate to the plot, but also playing with the slang use of "Spanish coin" meaning false compliments) to its triumphant ending it both follows the rules for a regency and gently subverts them. The heroine is as much Spanish as English, and the hero is Spanish--I won't given his full title, too long. The historical research provides a solid, but not obtrusive background.