Simon de Montfort was a 13th-century nobleman and military leader from France who played a significant role in the history of England. He is best known for leading the baronial revolt against King Henry III and for his efforts to establish a more representative form of government. De Montfort's actions led to the first elected parliament in 1265, which included commoners alongside nobles. Born around 1208, de Montfort was the son of a prominent French noble. He became the Earl of Leicester after marrying Eleanor, the sister of Henry III. His legacy is often associated with the development of parliamentary democracy in England, as he advocated for the inclusion of various social classes in governance.