When Richard died in 1199, John became King. Unlike his brother, John tended to stay at home and run his kingdom on a day to day basis. John, however, continued his brother's harsh tax policy. Because John lacked Richard's heroic image and charisma, his subjects began to hate him for his constant demands for more tax money.
He also fought with the Pope and the Catholic Church who excommunicated him for refusing to accept the Church's choice to become Archbishop of Canterbury. John retaliated by taxing the Church, confiscating its lands and forcing many priests out of the country.
Angry over John's abuses of power, English land barons conspired to stage a rebellion around 1212, but John foiled them by saving face with the Pope, who ended the excommunication.
After a failed invasion of France, John was weakened politically and demanded more taxes from the barons. The barons countered with a demand for a charter to reinstate freedoms granted by some of his predecessors. John refused to write a charter and the barons refused pay taxes.
After a long stalemate, rebellion was once again in the air. King John, the barons, the Church and others met at Runnymede in June 1215 to hammer out a truce. In the end, John put his seal to the Magna Carta and ended the immediate threat to a civil war in England. The barons got much of what they wanted, favorable feudal laws and corrections of John's abuses of power. John surrendered significant power but likely never intended to honor the agreement. He asked the Pope to cancel the agreement, which was granted... and by September 1215, John's armies were attacking the barons' castles.. and civil war erupted.
In October 1216, King John died. His nine-year old son, Henry, was crowned and the Magna Carta was reinstated, with the full support of the Pope.