Prince Regent John, also known as John of England, was a historical figure who lived during the late 12th and early 13th centuries. He was the youngest son of King Henry II and Eleanor of Aquitaine. John became known for his contentious reign, marked by conflicts with the nobility and his eventual loss of territories in France. In 1215, John faced a rebellion from his barons, leading to the signing of the Magna Carta, a foundational document that limited the powers of the monarchy and established certain legal rights. His reign is often viewed as a turning point in the development of constitutional governance in England.