For what purpose were the parliament in England, the states general in France, the Cortes in Spain created?

English Parliament
The English Parliament was convened for the first time at the end of the 13th century and consisted of representatives of the nobility and clergy. The preconditions for the emergence of parliament were the signing of the Magna Carta, according to which the king could not independently raise taxes. After Edward II issued a statute in 1322, which proclaimed the election of the king, parliament began to play an increasing role in the history of England. However, at that time representatives of the nobility and clergy were invited to parliament. Under Edward III, opposition to the House of Lords arose – the House of Commons. Its peculiarity was that it consisted of two chambers: the House of Lords and the Commons. Thus, a system of containment took place, in which none of the chambers could take over the full power. The king could not pass laws without the consent of parliament.

States general
The states-general became the successor to the king’s council, which met before the beginning of the 14th century. Such meetings were attended not only by representatives of the nobility and clergy, but also representatives of cities. The states-general did not change these traditions, so representatives of the clergy and nobility, as well as the third estate – in this case, the wealthy townspeople – were convened. Whatever the number of representatives of each class, they were given only one vote. During the Hundred Years War, the importance of the states-general increased more and more, after which the kings, feeling the threat of such fees, began to replace it with a collection of notables.

General Cortes
The first Cortes were created in the 12th century. As in the English parliament, only the privileged strata of the population – the nobility and the clergy – could take part in them. However, already at the end of the XII century, noble representatives of cities received representation in the General Cortes.

Common features can be traced between these institutions:
initially, they contained only those estates on which the king’s power rested;
representation of the people on behalf of the third estate;
at some point became the main legislative bodies;
limiting the power of the monarch.