I just finished Death of the Duchess by Elizabeth Eyre, a mediocre mystery set in Renaissance Italy.

The characters are OK but the mystery is a little lackluster and the author (really 2 authors under a pen name) don't really take advantage of the setting. Other than being told it is Renaissance Italy, there is not much that clearly points to that setting in the story. It could as easily been almost anywhere where nobility existed, before the 20th century.