Any good novels about the Medici?

Asking for a friend who wants to read a good historical novel about the Medeci’s and/or Florence during their rule. I’m mobile and don’t have access to my usual readers advisory sources; can anybody recommend a well researched and well-written relevant novel?

The only one I can think of offhand is AGONY and the ECSTASY, which is actually more set in Rome and about Michelangelo and as far as research quality goes Michelangelo is straight, so I’m not really sure it would qualify.
Thanks for any recs.

I remember an okay period thriller called The Medici Guns. Certainly there are better ones out there.

I just finished The Shepherdess if Siena: A Novel of Renaissance Tuscany by Linda Lafferty. It includes some members of the de Medici family but it cycles through several characters from a peasant shepherdess, her godfather, a painter, through Francesco, Isabella, and Ferdinando de Medici. it covers 20-25 years.

It seems to have been well-researched. I enjoyed it.

If you’re willing to go into genre fiction, The Palace by Chelsea Quinn Yarbro is pretty good. It’s the second book in her Saint-Germain series and it’s set in 15th century Florence with Lorenzo de Medici appearing as a supporting character. Saint-Germain is a vampire (based on a real historical character who lived in 18th century France) but Yarbro did a lot of historical research and gives a good account of the times and places where her books are set.