The Red Queen Philippa Gregory - Explain the Reason for Reading the Book

In a earlier post of mine, I had finished reading Lady of the Rivers, which was about Japquetta and her journey through the Royal Court of England and the people she met. One of the people she met was Queen Margaret, who was married to the King while she was in court. The Red Queen, is about Margaret and her journey to the English court with a backround of French. When I read the Lady of the Rivers, Margaret was introduced later in the book so I did not get to know that much about her past and that only she was desperate for an heir to continue the throne in her name.