February 20– Pope Honorius III directs the Franciscan Archbishop of Toledo, Rodrigo Jiménez de Rada, to lead the Franciscans in converting Moroccan Muslims to Christianity.
March 4– Just before dawn, a great conjunction between Saturn and Jupiter is observed from Earth. The conjunction is more significant than other occurrences because the separation of the two planets as visible in the sky of Earth (2.1 arcminutes or 1/30th of one degree of arc) will not be closer again until March 8, 4523 CE, and the close conjunction is the most easily visible from Earth until the conjunction of December 21, 2020.
March 26–Frederick II, Holy Roman Emperor issues the Golden Bull of Rimini, in which he grants Teutonic Knights the right to all of the lands they will get during the mission in Prussia; he also declares himself a senior of the Teutonic Order and Poland, as well as the universal ruler of Christian Europe.
April – June
April 5– The Treaty of Melun is concluded between France (ruled by King Louis VIII) and Flanders, ruled jointly of by Jeanne, Countess of Flanders and Hainaut, with France agreeing to release her husband Count Ferrand (who had been a prisoner of war since 1214 in return for payment by Flanders of 50,000 livres in two installments, with Lille, Douai, and Sluis to be occupied by French troops until the debt is paid. In addition, Ferrand and Jeanne agree to swear their loyalty to King Louis, and to require that all Flemish nobles, knight and burghers take a similar oath of loyalty, including a promise not to support the Count of Flanders if he backs out of the treaty.
June 7– King Louis VIII of France begins the Crusade against the Cathars (Albigensians) in southern France and against Raymond VII, count of Count of Toulouse. Over the next three months, the Crusaders capture the cities of Béziers, Carcassonne, Beaucaire and Marseille and by Avignon's surrender on September 9, Louis forces the region of Languedoc into submission, and reasserts his authority upon the autonomous municipalities of his estates. Most cities have to accept the authority of Ramon Berenguer IV, count of Provence, but Marseille and Nice rebel.
August 8–Siege of Avignon: After two months without forcing the defenders of Avignon to surrender from lack of food, King Louis VIII gives the order to assault the walls of the city and Guy II, Count of Saint-Pol, begins the second phase of the siege, digging trenches facing the city walls – which are connected on both sides of the Rhône with pontoon bridges. Firing from the fortress towers, the defenders repulse the attack and Count Guy is killed by a catapulted stone on the same day.
August– At Xingqing in what is now China's Yinchuan province, Emperor Xianzong of the Western Xia Empire dies after a three-year reign, and is succeeded by his nephew, Li Xian. The Mongols under Genghis Khan force the surrender of Western Xia the following year, bringing an end to the Yinchuan province as a separate nation.
September 9– After Avignon's defenders negotiate a peaceful resolution with the French Army by the payment of an indemnity of 6,000 marks, the gates of the walled city are opened and Louis enters the city without violence.
November 29– The coronation of Louis IX as King of France takes place at the Reims Cathedral at the direction of Queen Blanche, who also orders the defeated French nobles from the Albigensian Crusade to swear allegiance to her son.
December 23–Jean Halgrin, the French Roman Catholic archbishop of Besançon, is offered the opportunity to be the Catholic patriarch of Constantinople, but declines the position because of health issues.F. Vigouroux (1912). Dictionnaire de la Bible. Vol.I. Letouzey et Ané.
By place
Europe
The Teutonic Knights undertake a new Crusade, attempting to subdue the pagan Prussians, who occupy a part of the Baltic coast. They are invited to Poland by High Duke Konrad I of Masovia, a grandson of Bolesław III Wrymouth. Their task is to defend Masovia against raids of the Prussians. After defeating them, the German knights set up their own state, which they named after the pagan people they have all but annihilated – Prussia.
↑Michael Ott, "Pope Honorius III", The Catholic Encyclopedia, Volume 7 (New York: Robert Appleton Company, 1910)
↑Jean Létanche (1907), Les Vieux Châteaux, Maisons fortes et Ruines féodales du canton d'Yenne en Savoie[Old Castles, Fortified Houses and Feudal Ruins of the Canton of Yenne in Savoy], Le livre d'Histoire-Lorisse, ISBN9782843738135{{citation}}: ISBN / Date incompatibility (help)
↑Richards, D. S. (2010). The chronicle of Ibn al-Athīr for the crusading period from al-Kāmil fīʼl-taʼrīkh. Ashgate Publishing. p.269. ISBN9780754669524.
↑Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1996). Handbook of British Chronology (Third reviseded.). Cambridge, UK: Cambridge University Press. p.85. ISBN0-521-56350-X.
↑Brezinski, Richard (1998). History of Poland: Old Poland – The Piast Dynasty, pp. 22–23. ISBN83-7212-019-6.
↑Picard, Christophe (2000). Le Portugal musulman (VIIIe-XIIIe siècle. L'Occident d'al-Andalus sous domination islamique. Paris: Maisonneuve & Larose. p.110. ISBN2-7068-1398-9.
↑Man, John (2004). Genghis Khan: Life, Death and Resurrection, p. 214. ISBN978-0-312-36624-7.