ORIGINS
Parliament in England originally consisted of one loose 
grouping of representatives - primarily the King's chief 
advisors (the barons and bishops). In 1264, however, 
the barons rebelled against Henry III - and briefly took 
over the government of the country under Simon de 
Montfort. 

De Montfort summoned two parliaments to support his cause -
and for the second of these, in 1265, he also summoned knights 
from the shires, and elected Burgesses from the towns. This group eventually evolved into the Commons. Later, during the 14th century, Lords and Commons began to band together, and eventually divided into two assemblies.