Simon de Montfort was a French-English nobleman who played a significant role in the political and military events of 13th-century England. He is best known for leading the baronial opposition against King Henry III and establishing the first English parliament with elected representatives. De Montfort's efforts to limit the king's power and promote the interests of the nobility and the common people had a lasting impact on the development of parliamentary democracy in England. His legacy continues to be studied and celebrated as a pivotal figure in the history of English political reform.