“Some years ago, my father came home with a carton of old letters that time and humidity had compacted into wads of barely legible paper,” Andrea di Robilant tells us as he begins this spellbinding true story of love in eighteenth-century Venice. In the attic of their old family palazzo on the Grand Canal, his father had found the love letters of their ancestor Andrea Memmo, one of the last great Venetian statesmen, to a beautiful half-English girl named Giustiniana Wynne. Some of the letters were written in code, which di Robilant and his father cracked to reveal an illicit passion: Giustiniana was not of the elite ruling class and would never have been considered a suitable match for Andrea. But their acts of devotion were startlingly brazen. As their courtship unfolds, they plot elaborate marriage schemes that offend everyone, arrange secret trysts in borrowed rooms, cause trouble for the servants who must ferry their forbidden correspondence, and even weather an unwanted pregnancy, from which Giustiniana, with her wits and ingenuity and some crucial assistance from the infamous Casanova, emerges unscathed.

Andrea di Robilant, heir to the lovers’ legacy, captures them in the twilight of the golden era of Venice, with forays to the colorful social circles of London and Paris along the way. His sparkling, well-paced narrative evokes the world of mask-wearing men and ladies attending Goldoni plays and gambling at the Ridotto—bringing to life, 250 years later, a tale of unbounded passion and rich historical intrigue.

• HistoryItalyTravel