"The Constant Princess" is a historical novel by Philippa Gregory that tells the story of Catherine of Aragon, the first wife of King Henry VIII of England. The narrative explores her life from childhood in Spain to her marriage and struggles in England, highlighting her resilience and determination. The novel delves into themes of power, loyalty, and betrayal, portraying Catherine as a strong and intelligent woman navigating the complexities of royal life. It provides insight into the political landscape of the time, including the significance of the Tudor dynasty and the challenges faced by women in a patriarchal society.