Wyrd Sisters, by Terry Pratchett, is one of the books of the Discworld series. In this wonderful book there are three witches.
These three have to spend time moving about in the world of royalty. This does not follow along with their other lives where they don't have a leader. This leads to such fun and laughter, on the part of the reader.
For those that enjoy fantasy or Terry Pratchett books, this should be a book in their line-up. It is great fun.