1231 CE
Pope Gregory IX issues Parens scientiarum. The bull assures the independence and self-governance of the University of Paris. Ögedei Khan orders the invasion of Korea. A Mongol army crosses the Yalu River and quickly secures the surrender of the border town of Uiju. The Mongols are joined by Hong Pok-wŏn, a Goryeo general, who takes their side with his subordinates numbering some 1500 families. Spring – Hubert de Burgh, Earl of Kent becomes a powerful lord in the Welsh Marches, controlling the castles at Cardigan and Carmarthen. He begins to threaten the local Welsh leaders, Llywelyn the Great launches a campaign against Norman lordship in Wales.
Geopolitics & Diplomacy
- August 13 – King Henry III orders the sheriffs of Hampshire, Dorsetshire and Wiltshire to give Simon de Montfort the possession of the lands of his father, Simon de Montfort the elder.source
- December – Henry III ends his Welsh campaign and makes peace with Llywelyn the Great.source
- Emperor Frederick II promulgates the Constitutions of Melfi (Liber Augustalis), a collection of laws for Sicily, as well as the Edict of Salerno, regulating the exercise of medicine and separating the professions of physician and apothecary, and requiring medical schools to practice dissection.source
Conflict & Security
- August – Ögedei Khan orders the invasion of Korea. A Mongol army crosses the Yalu River and quickly secures the surrender of the border town of Uiju. The Mongols are joined by Hong Pok-wŏn, a Goryeo general, who takes their side with his subordinates numbering some 1500 families.source
- War of the Lombards: Richard Filangieri sails for Beirut, where the town is handed over to him. He occupies Sidon and Tyre – while other Lombard forces appear before Acre. At Acre, Filangieri summons a meeting of the High Court and shows letters from Frederick II appointing him as ambassador (baili).source
- Siege of Kuju: Mongol forces besiege the city of Kuju. They deploy assault teams who man siege towers and scale ladders. Despite the fact the Goryeo army is heavily outnumbered, the garrison refuses to surrender.source
- Castillian forces under King Ferdinand III ("the Saint") re-conquer the city of Quesada.source
- Spring – Hubert de Burgh, Earl of Kent becomes a powerful lord in the Welsh Marches, controlling the castles at Cardigan and Carmarthen. He begins to threaten the local Welsh leaders, Llywelyn the Great launches a campaign against Norman lordship in Wales.source
- Battle of Jerez: Ferdinand III defeats Emir Ibn Hud of the Taifa of Murcia.source
- Autumn – Frederick II appoints Marshal Richard Filangieri as his imperial legate, and sends an expeditionary army of mostly Lombards for the defense of Jerusalem. He gathers some 600 knights, 100 "sergeants-at-arms", 700 armed infantrymen, and 3,000 marines. The army is supported by 32 war-galleys.source
Religion & Belief
Disasters & Accidents
- April 9 – A huge fire breaks out at night in the southeast of Hangzhou during the Song dynasty. Fighting the flames is difficult due to limited visibility. When the fires are extinguished, it is discovered that an entire district of the city (some 10,000 houses) has been consumed by the flames.source
Culture & Society
- The University of Cambridge is recognised by a writ of authority over its townspeople from Henry III.source
Births
- March 17 – Shijō (Mitsuhito), emperor of Japan (d. 1242)source
- Roger Mortimer, English nobleman and knight (d. 1282)source
- John of Burgundy, French nobleman and knight (d. 1268)source
- Philip of Castile, Spanish prince and archbishop (d. 1274)source
- John de Warenne, English nobleman and knight (d. 1304)source
- Yolanda of Vianden, Luxembourgish prioress (d. 1283)source
- James Salomoni, Italian Dominican priest and prior (d. 1314)source
- Guo Shoujing, Chinese astronomer and engineer (d. 1316)source
- Tommaso degli Stefani, Italian painter and artist (d. 1310)source
Deaths
- May 7 – Beatrice II, French countess palatine (b. 1193)source
- June 13 – Anthony of Padua, Portuguese priest (b. 1195)source
- July 2 – Henry I, German nobleman (House of Zähringen)source
- August 3 – Richard le Grant, archbishop of Canterburysource
- August 28 – Eleanor of Portugal, queen consort of Denmarksource
- September 15 – Louis I, German nobleman (b. 1173)source
- September – Ibn Muti al-Zawawi, Almohad jurist, philologian and writersource
- November 3 – Władysław III, Polish nobleman (b. 1167)source
- November 9 – Abd al-Latif al-Baghdadi, Abbasid physician (b. 1162)source
- November 17 – Elizabeth, Hungarian princess (b. 1207)source
- November 28 – Valdemar the Young, king of Denmarksource
- December 7 – Richardis, German noblewoman (b. 1173)source
- December 11 – Ida of Nivelles, Flemish nun and mysticsource
- December 25 – Folquet de Marselha, French bishopsource