Feudalism was the economic and political system that developed in Europe during the Middle Ages, but unfortunately ended with the help of the Magna Carta.
Do you promise to follow common law as well as the traditions of us and the church?
Then you can stay king as long as you continue to abide.
King John began to arrest people without a fair trial, upsetting many people. Most of those who were arrested King John couldn't give reasoning of why, upsetting those people even more.
King John began to demand money and began to tax barons and common people very heavily! People's rage began to escalate even more, especially the barons. This was the final straw and the barons decided to put matters into our own hands.
Now I can't possibly be less powerful than a peasant!
Wait I can't loose my power if i remind the king of the signing...
The king's own barons held a meeting where the king is forced to sign a document know known as the Magna Carta, otherwise he can no longer to be king. When he signed the paper, the barons agreed that he can stay king, and in return he must follow common law and the traditions of the church and barons, such as agreeing to consult the barons and church before he can give special taxes.
This change not only strengthened the power of royalty while weakening the power of the nobles, but it also weakened feudalism by moving power to the common people.
Afterwards, it left the nobles with less power and the common people gained more power than they originally had. However, the nobles were able to keep that power by enforcing the law every time the king breaks the law, reminding him that he may no longer be king if he continues to do this.