Richard I succeeded Henry II. He spent less than a year of his reign in England because he left for the Holy land to take part in the third crusade. During his absence , his brother John tried to usurp his place. When Richard died , the English and Norman barons chose John to be king. In the popular perception , John is "Bad king John " . He abused of the feudal system ,he urged land and profits of the barons. There was a rebellion and so John agreed to sealed the Magna Carta.
The magna carta was written in 1215 and had a number of inducements against John's rule. For example the king couldn't imprison illegally, he couldn't take off the private property ; he could administrate swift justice. There was a committee of 25 barons to oblige the king to respect the agreement.
Habeas corpus is a written document and legal action to determinate the legality of detention.
It establish if person is to be in prison or not and the reasons to be imprison legally. After you have a trial. Habeas corpus doesn't determine guilt or innocence . It follow the concept of the article 39 of Magna carta .
Habeas corpus was very important because it represented a protection against the king and barons . Today habeas corpus is still a protection against the state.