Medieval parliaments were usually only called to 
Westminster when circumstances required, and often 
consisted only of the barons and dignitaries of the Church. 
However, there were occasions when more general 
approval was required. 

Between 1294 and 1297, Edward I's high-handed policies 
landed him in the position of fighting three wars at once - in 
Wales, Scotland, and France. In order to raise enough revenue, 
he called a Parliament, in 1295, that proved so similar to national gatherings in later centuries that it has been called the 'Model Parliament'.

Those summoned included the lords lay and spiritual, two knights from each county, two citizens from each city and two burgesses from each 
borough, and (for the first time) lesser clergy - a total of around 400 representatives. 'What touches all', the writ of summons said, 'should be approved by all'.