1258

By area

Global

• The observed effects of an eruption of the Indonesian volcano Mount Rinjani, in late 1257, include the following anecdotal accounts: dry fog in France; lunar eclipses in England; severe winter in Europe; a "harsh" spring in northern Iceland; famine in England, western Germany, France, and northern Italy; and pestilence in London, parts of France, Austria, Iraq, Syria, and southeast Turkey.

  Asia

• February 10 - The Siege of Baghdad ends with a battle, in which Hulagu Khan's Mongol forces overrun Baghdad, then the leading center of Islamic culture and learning, and capital of the Abbasid Caliphate. They burn the imperial city to the ground, killing as many as 1,000,000 citizens, and destroy the House of Wisdom, containing countless precious historical documents, and books on subjects ranging from medicine to astronomy.
• June 25 - War of Saint Sabas: In the Battle of Acre, the Venetians defeat a larger Genoese fleet sailing to relieve Acre.
• The Chinese era Baoyou ends, in the Southern Song Dynasty of China.
• Korea surrenders to the Mongols, ending the effective resistance of the Choe faction within Korea.
• The Mongol Empire invades the Đại Việt. The Mongol army is soon defeated by the Đại Việt forces.

  Europe

• May 11 - The Treaty of Corbeil is signed between James I of Aragon and Louis IX of France. The French king, as the heir of Charlemagne, formally renounces his feudal overlordship over Catalonia, while the Aragonese king renounces his claims over Occitania.
• August 25 - George Mouzalon, regent of the Empire of Nicaea, is assassinated in Magnesia ad Sipylum, as part of a conspiracy led by nobles, under future emperor Michael VIII Palaiologos.
• Llywelyn ap Gruffudd declares himself Prince of Wales. He is the final ruler of an independent Wales, before its conquest by the English.
• King Henry III of England is forced by seven powerful barons to accept the Provisions of Oxford.
• Gissur Þorvaldsson is made Earl of Iceland, by King Haakon IV of Norway.
• The Mongol Golden Horde attacks Lithuania.
• The Battle of Karydi ends the War of the Euboeote Succession in a crushing victory for William II of Villehardouin, Prince of Achaea.
• Epirote–Nicaean conflict.

  By topic

Markets

• In Genoa, the Republic starts imposing forced loans, known as luoghi, to its taxpayers; they are a common resource of medieval public finance.

  Religion

• Civil unrest in northern Italy spawns the medieval musical form of Geisslerlieder, penitential songs sung by wandering bands of Flagellants.
• The Mongols murder the Abbasid Caliph, and end the long-standing Islamic Empire.

  Births

• Osman I, founder of the Ottoman Empire
• Trần Nhân Tông, emperor of Vietnam
• Lady Nijō, Japanese concubine and Buddhist nun
• probable
• * Arghun, fourth Ilkhanate ruler of Iran
• * Henryk IV Probus, Duke of Wrocław

  Deaths

• February - Sulaiman Shah, Abbasid soldier
• February 20 - Al-Musta'sim, last Abbasid Caliph of Baghdad
• April 5 - Saint Juliana of Liège
• June 2 - Peter I, Count of Urgell
• July 22 - Meinhard I, Count of Gorizia-Tyrol
• August 18 - Theodore II Laskaris, emperor of Nicea
• August 25 - George Mouzalon, regent of the Empire of Nicaea
• November 10 - William de Bondington, Bishop of Glasgow
• Abul Hasan ash-Shadhili, Moroccan spiritual leader
• Clement of Dunblane, first Dominican bishop in Britain
• Hong Bok-won, Goryeo commander who later served the Mongol Empire
• Ingerd Jakobsdatter, Danish countess