These are the books by Mary Hoffman that are reviewed on this site:
Lucien travels to sixteenth century Belleza and becomes deeply involved in political intrigue.
Georgia follows Lucien but she finds herself in sixteenth century Remora. There she meets other stravaganti, including Lucien, but her role turns out to be quite different.
Sky joins the Brotherhood of Stravaganti and they must all work together to save the city of Giglia, stronghold of the great di Chimici family.