Lords and commons
England's kings were always short of money to pay for their wars. So they often had to ask parliament for new taxes. They found that they could not manage without parliament's help.
The most important men in parliament were still the lords. Wise kings listened to their advice. Two kings, Edward II and Richard II, were deposed (thrown out) in the fourteenth century because they would not listen to the lords. By 1450, when Henry VI was king, the great lords were stronger than the king.
At the same time, the commons had won some rights. After 1327, they always took part in parliaments. By the fifteenth century, new taxes and statutes had to be passed by the commons as well as the lords. But there was still no 'House of Commons' or 'House of Lords'. Parliament did not always meet in London, and there were no 'Houses of Parliament'.
Walter Robson: Medieval Britain; Oxford University Press, 1991/2000, page 33