John was not very good in battle, losing vast areas of territory in France that England once ruled over. This earned him the nicknames 'lackland' and 'softsword'.
The Pope also wanted Henry's brother, Richard, to become Holy Roman Emperor, which was an important job. This meant Henry would feel pressured to help pay for the Pope's wars
By 1254 Henry's relationship with the barons had deteriorated - they were angry about his foreign influence, tax increases to pay the Pope, and that Henry's French family were given jobs in the English court and Italian clergy were given top jobs in the Church
The Provisions of Oxford, extended in 1259 in the Provisions of Westminster, reformed local government and gave more power to the less powerful and wealthy in society
This angered some older barons, who felt the reforms were getting in the way of their local interests, and some younger barons were angered as they were not elected to the council and therefore lost their influence
Henry gained the support of those barons who did not like de Montfort and the Provisions of Oxford. Henry wrote to the Pope and asked for his permission to cancel the provisions. In 1261 the Pope agreed, so Henry appointed his own men to the Great Council
Henry ruled as badly as he had before, and after three years the barons called upon Simon de Montfort. The Second Barons' War began. At the Battle of Lewes in 1264 de Montfort captured the king and imprisoned his son, the young Prince Edward. Simon de Montfort was now in charge and England was on its way to becoming a republic