Simon de Montfort's Parliament in the context of "Parliament"

A parliament is a type of legislature, or law-making body, of a state. Generally, a parliament has three functions: representing the electorate, making laws, and overseeing the executive government via hearings and inquiries. Its role is similar to that of a senate, synod or congress; a parliament is the institutional form of parliamentary systems based on the fusion of powers. The term parliament is commonly used in countries that are current or former monarchies. Some contexts restrict the use of the word to parliamentary systems, although it is also used to describe the legislature in some presidential systems (e.g., the Parliament of Ghana), even where it is not in the official name. A parliament is typically made up of elected members, who are legislators.

Historically, parliaments included various kinds of deliberative, consultative, and judicial assemblies. Parliamentary gatherings in the Middle Ages began to establish that monarchs were subject to law and first summoned representatives of common people, notably the Cortes of León in 1188 and an English parliament in 1265. During the early modern period, the Glorious Revolution of 1688 in Britain established the primacy of parliamentary sovereignty, through which the rule of law could be enforced. Many other modern concepts of parliamentary government developed in the Kingdom of Great Britain (1707–1800) and were exported to other countries around the world. Expansion of suffrage in the 19th and 20th centuries led to many parliaments becoming democratically elected.

Simon de Montfort, 6th Earl of Leicester, 1st Earl of Chester (c. 1208 – 4 August 1265), also known as Simon V de Montfort, was an English nobleman of French origin and a member of the English peerage, who led the baronial opposition to the rule of King Henry III, culminating in the Second Barons' War. Following his initial victories over royal forces, he became de facto ruler of England, and played a major role in the constitutional development of England.

During his rule, Montfort called two famous parliaments: the Oxford Parliament stripped Henry of his unlimited authority, while the second included ordinary citizens from the towns. For this reason, Montfort is regarded today as one of the progenitors of modern parliamentary democracy. As Earl of Leicester he expelled Jews from that city; as he became ruler of England he also cancelled debts owed to Jews through violent seizures of records. Montfort's party massacred the Jews of London, Worcester and Derby, killing scores of Jews from Winchester to Lincoln. After a rule of just over a year, Montfort was killed by forces loyal to the king in the Battle of Evesham.