Upon his death, Elizabeth was imprisoned by her half-sister Mary. Elizabeth realized quickly that she needed her wits about her to avoid being embroiled
in political intrigue. She was very good at this.

Mary did not like Elizabeth (a Protestant), nor did she trust her, but she couldn't kill the princess (who had many followers), so she kept Elizabeth as a prisoner for several years. When Elizabeth was twenty-five, Mary died, and Elizabeth became Queen.