Duke's Diamonds: Regency Royal 11

M.C. Beaton (1936-2019) was the author of both the Agatha Raisin and Hamish Macbeth series, as well as numerous Regency romances. Her books have been translated into seventeen languages and have sold more than twenty-two million copies worldwide. She is consistently the most borrowed UK adult author in British libraries, and her Agatha Raisin books have been turned into a TV series on Sky.