 Simon de Montfort 's parliament of 1265 is sometimes referred to as the first English parliament , because of its inclusion of both the knights and the burgesses , and Montfort himself is often regarded as the founder of the House of Commons . The 19th century historian William <unk> popularised the <unk> " Model Parliament " of Edward I as the first genuine parliament ; however , modern scholarship questions this analysis . The historian David Carpenter describes Montfort 's 1265 parliament as " a landmark " in the development of parliament as an institution during the medieval period . 
