"Protector of the Small" is a fantasy book series by Tamora Pierce that follows the journey of Keladry of Mindelan, a young girl who aspires to become a knight in the Kingdom of Tortall. Set in a medieval-like world, the series explores themes of courage, friendship, and the challenges faced by a female knight in a male-dominated society. The series consists of four books: "First Test," "Page," "Squire," and "Lady Knight." Throughout her training, Kel confronts various obstacles, including prejudice and personal doubts, while developing her skills and proving her worth as a knight. The story emphasizes the importance of perseverance and integrity.