- May 26 - German Frederick II, Holy Roman Emperor, grants bishops sovereign rights.
- May – St. Francis of Assisi resigns from the leadership of the Franciscan Order.
- August 8 – Livonian Crusade: Estonians defeat the invading Swedes, in the Battle of Lihula.
- November 22 – Frederick II is crowned Holy Roman Emperor, by Pope Honorius III.
- The Mongols first invade the Khwarazmian Empire; Bukhara and Samarkand are taken.
- The Dominican Order is approved by Pope Honorius III.
- Conrad of Masovia drives out the heathen Prussians, from the Masovian territory of Chelmno Land.
- Trial by ordeal is abolished in England.
- The German Hohenstaufen dynasty, which had ruled Sicily since 1194, adopts Palermo as its principal seat.
- Dordrecht receives city rights, making it the oldest city in the present-day Holland area.
- Ljubljana receives its town rights.
- The Islamic lands of Central Asia are overrun by the armies of the Mongol invader Genghis Khan (ca. 1155–1227), who lays waste to many civilizations, and creates an empire that stretches from China to the Caspian Sea.
- The Thai Kingdom of Sukhothai is established.
- Saint Benedict of Nursia is canonized by the Roman Catholic Church.
- Gothic architecture becomes increasingly popular in Europe.
- The rebuilding of the Cathedral of Chartres, which had been destroyed by a fire in 1194, is completed.
- The rebuilding of Amiens Cathedral begins.
- The rebuilding of York Minster begins.
- The building of the Salisbury Cathedral begins.
- The rebuilding of the city of London begins.
(The Jews were accused of a ritual murder. A crowd stormed the synagogue where the Jews had gathered. The threat was baptism or death. The Jewish quarter including the synagogue was razed, many Jews were tortured and killed. Among the martyrs were Shem Tov ha-Levi, and Rabbi and Mrs. Shmuel Kalonymos.)
- July 29 – 10-year-old Emperor Go-Horikawa ascends to the Chrysanthemum Throne of Japan.
- Mid-December – John III Doukas Vatatzes becomes Byzantine Emperor (in the Empire of Nicaea).
- A large and highly efficient Mongol army, dispatched under Subutai by Genghis Khan to Georgia, defeats two Georgian armies around Tbilisi, but lacks the will or equipment to besiege the city.
- Genghis Khan enters the Indus Valley in modern-day Pakistan.
- Majd al-Mulk al-Muzaffar, the grand vizier of Greater Khorasan, is killed in a genocide by the Mongol invaders.
- The Maya of the Yucatán revolt against the rulers of Chichen Itza.
- Sultan al-Kamil, son of al-Adil ("Saphadin"), who was a brother of Saladin, offers Jerusalem to the Crusaders for ten years in return for Damietta, which the Crusaders eventually give up, in exchange for a safe retreat from the Nile Delta.
- The city of Nizhny Novgorod, Russia is founded.
- February – At Carrión the king of Castile, Ferdinand III, announces his intention to resume the Reconquista against al-Andalus. This same year, the Almohad caliph, Yusuf II al-Mustansir, dies and is succeeded by Abu Muhammad al-Wahid, but in al-Andalus, two competing pretenders also claim their rights to the throne: Abu Muhammad Ibn al-Mansur al-Adil in Seville, and Abu Muhammad abu Abdallah al-Bayyasi in Córdoba, Andalusia. The chronic political instability on the Muslim side allows the Castilian prince to begin his campaign victoriously in October, with the capture of Quesada, Spain.
- The last Muslim inhabitants are expelled from Sicily and Malta.
- Livonian Crusade: The Livonian Brothers of the Sword defeat the Estonians, and reconquer the captured strongholds on the Estonian mainland. With the surrender of the Tartu stronghold, only the islands of Saaremaa and Muhu remain under Estonian control.
- Theodore Komnenos Doukas, ruler of the Despotate of Epirus, captures Thessaloniki, beginning the de facto Byzantine Empire of Thessalonica.
- The University of Naples is founded.
- September 14 (approximate date) – St. Francis of Assisi, while praying on the mountain of Verna during a 40-day fast, has a vision, as a result of which he receives the stigmata. Brother Leo, who is with Francis at the time, leaves a clear and simple account of the event, the first definite account of the phenomenon of stigmata.
- King Louis VIII of France launches a large southward offensive against the Albigensians and the Count of Toulouse. Ramon Berenguer IV, Count of Provence, uses the opportunity to reassert his authority upon the autonomous municipalities of his estates (October). Most cities have to accept the authority of the Count, but Marseille and Nice rebel.
- November 8 – Louis IX of France starts to rule, on the death of Louis VIII.
- King Sancho II of Portugal launches a large offensive against the Muslims, and takes the city of Elvas.
- Frederick II, Holy Roman Emperor, calls the Imperial Diet of Cremona.
- Nuneaton is granted a chartered market status, by King Henry III of England.
- Rǫgnvaldr Guðrøðarson, King of the Isles, is overthrown as ruler of the Kingdom of the Isles, and replaced with his half-brother, Olaf the Black.
Arts and culture
- In Norway, Brother Robert writes Saga Af Tristram ok Ísodd, one of the rare fully surviving versions of the legend of Tristan and Iseult.
- Sukaphaa, the first Ahom king, establishes his rule in Assam. The Ahom kings reign for close to 600 years.
- April 25 – Conrad IV of Germany becomes titular King of Jerusalem, with Frederick II, Holy Roman Emperor as regent.
- June 28 – The Sixth Crusade is launched from Brindisi by Emperor Frederick II, after delays due to sickness and an excommunication from Pope Gregory IX.
- Baldwin II becomes emperor of the Latin Empire in Constantinople, with John of Brienne as regent.
- The Transylvanian town of Reghin is first mentioned, in a charter of Andrew II of Hungary.
- Spain: King James I of Aragon launches a major offensive against the Muslims in Majorca. The same year, in Murcia, confronted by increasing Christian pressure, the cadi (soon to be called emir), Ibn Hud al-Yamadi, denounces the Almohads and acknowledges the Abbasids as legitimate caliphs, in effect declaring independence. Other notable Christian success: Alfonso IX of León conquers Mérida.
- The city of Tournai emits its first recorded life annuity, thus confirming a trend of consolidation of public debts started ten years earlier, in Reims.
- The first evidence is uncovered of the use of the Knights Templar as cashiers by the king of England, to transfer safely important sums to the continent, using letters of exchange. This shows that large transfers could take place across Europe, even before the emergence of important networks of Italian merchant-bankers.
- February 18 – Sixth Crusade: Frederick II signs a ten-year truce with al-Kamil, regaining Jerusalem, Nazareth, and Bethlehem with neither military engagements, nor support from the papacy.
- March 6 (Shrove Tuesday) – The 2-year University of Paris strike begins with a student riot.
- March 18 – Sixth Crusade: Frederick II crowns himself King of Jerusalem.
- April 12 – The Treaty of Paris brings the Albigensian Crusade to an end.
- April 23 – Alfonso IX of León conquers Cáceres.
- September 12 – The Catalan-Aragonese army, under the command of James I of Aragon, disembarks at Santa Ponça, Majorca, with the purpose of conquering the island.
- September 13 Ögedei was proclaimed Khagan of the Mongols from kurultai council.
- November 28 or November 29 – Battle of Olustra: Erik Eriksson is defeated, and deposed as king of Sweden by Knut Långe, who proclaims himself the new king.
- The Catholic Church permanently establishes the Inquisition, in the charge of the Dominican Order in Rome.
- Beverston Castle, Gloucestershire, England, is founded.
- Following the deadlock tie in the election of the Venetian Doge, the number of electors is increased from 40 to 41 in order to prevent such future occurrences.
- The University of Toulouse is founded in France.
- The city of Turku, Finland is founded.
- The city of Rapperswil is established by Count Rudolf II of Rapperswil.