One of the themes in the book is divorce, so I thought it would be interesting to say something about divorce in Italy, where Sofia's marriage takes place. The 19th century in general sees some early periods of an uptick for divorce legislation throughout Europe. By 1806 the Codice Civile made divorce available to the European peninsula. By the 1830s, when Italy had dissolved back into independent principalities, Piedmont King, Carlos, allowed divorce among non-Catholics. Roderick Phillips writes in his book, "Untying the Knot; a Short History of Divorce," that the Piedmont's positioning in a national movement for Italian of unification might have created a scenario where this divorce law was more widely adopted, but those hopes were quelled when his son, Victor Emmanuel II took the throne in 1852. Victor Emmanuel II abolishes divorce.
These dates are important to Sofia's story line. When the book opens, it's 1854. She's been divorced and living in London for three years, her divorce having taken place in 1851 before the official abolishment. Her husband's desire to have her back in wedlock plays off the conservative nature of Victor Emmanuel. Il Marchese, her husband, cannot receive recognition and advancement in the new, conservative court as a divorced man and since re-marriage after divorce was also an issue, it was not enough for him to simply offer to marry again. He must re-marry his legitimate wife in the eyes of the church. Hence, our villain's desire to have Sofia back specifically.