King Richard dies in 1199 from an arrow injury to the arm he got during a war and as a result of his death, his younger brother John becomes king of England.
King John had lost many battles and didn't have the same kind of courageous fame his brother Richard once had, so when he did something wrong others didn't give him the same slack they gave Richard.
I feel like the people and major landowners don't like me.
Nonsense, everybody loves you your majesty.
A group of rebellious landowners wanted no more of King John's extra taxation and (knowing that John had a reputation for being tyrannical) they wanted to be sure that John could no longer be above the English law and their rights.
Why do we have such a baaad King...waaaa.
John hast to be the worst.
Led by Robert Fitzwalter and the French army (which was under the command of the future Louis VIII of France), the group of rebellious major landowners (commonly known as the barons) warred on King John.
We are going to get what we want...justice!
The rebel barons had organised into a military faction and held London. After this had happened, John tried to make peace to the rebel barons and eventually got to meet them and try and fix what had happened by agreeing with them on something.
We've got London.
King John signed the general agreement that had been made in text and the rebels renewed their oaths of loyalty to John and copies of the charter were formally issued. The agreement is called the Magna Carta and it stops the king from doing particular things that are above the law or anyone's rights. Many later documents such as the US Constitution were based on the Magna Carta and that is why the Maga Carta is important to know about.