March 4 – King John of England ("Lackland"), hoping to gain the support of Pope Innocent III against the Barons, takes the oath to go on Crusade. By doing so, Innocent declares John to be his vassal and claims ownership of the whole kingdom (with political protection under church law).[2] On April 1, Innocent sends a letter to the Barons, asking them to halt their actions against John.
May 17 – The gates to London are opened by supporters of the rebellious Barons. The houses of Jews are targeted for ransacking and burning. The rebels, under Robert Fitzwalter, call for the English nobles still on the side of King John to join them, and repair the walls. The Tower of London, held by John's supporters, is too well defended to fall into the hands of the rebels.
June 15 – A large number of barons, led by Stephen Langton, archbishop of Canterbury, meet King John of England on an island in the Thames at Runnymede. They force John to sign Magna Carta, a document that grants liberties to the "free men" – the Barons, the church and the towns. He is subjected to the rule of law, by confirming the status of trial by jury, on June 19.[4]
Summer – Emperor Otto IV is excommunicated and forced to abdicate as ruler of the Holy Roman Empire. The German nobles, supported by Innocent III, again elect the 20-year-old Frederick II as King of the Romans who is crowned in Aachen, on July 25. The same day, Frederick takes the Cross and promises to go on Crusade.
August – King John of England rejects Magna Carta and writes to Innocent III – asking him to cancel the charter on grounds that he signed it against his will. At the same time, John continues to build up his mercenary army.
August 24 – Pope Innocent III annuls Magna Carta, freeing King John from its limitations. He annuls the charter on the grounds that John signed it because he is forced and that the document is illegal.
September 13 – King John of England seeks help from Innocent III in his fight against the Barons. In a letter, written while staying at Dover Castle, he states that the defense of England is the responsibility of God and the Pope.
October – The Barons offer the English crown to Louis of France and invite him to England. King John England confiscates the Barons' land and besieges Rochester Castle; the garrison is starved out and surrenders to him.
June 1 – Mongol conquest of Jin China: After the long Battle of Zhongdu, the Mongol forces capture Zhongdu (modern-day Beijing). Meanwhile, Genghis Khan has decamped to the edge of the grasslands and is on his way back to the Kherlen River. Without his restraining influence, the Mongols run wild. They devastate and ransack the city, killing thousands. The royal palace goes up in flames, and a part of the capital burns for a month.[8]
