Editing 1258 (section)

==== Europe ====
* [[May 11]] &ndash; [[Treaty of Corbeil (1258)|Treaty of Corbeil]]: King [[Louis IX of France]] ("the Saint") signs a peace treaty with King [[James I of Aragon]] ("the Conqueror"). Louis, heir of [[Charlemagne]], formally renounces his feudal overlordship over [[Catalonia]] (independent ''de facto'' since [[988]]), while James renounces his claims over [[Occitania]].
* June &ndash; [[War of the Euboeote Succession]]: Achaean forces under [[William of Villehardouin|William II Villehardouin]] defeat a coalition of Greek princes led by [[Guy I de la Roche]] ("Great Lord"), duke of [[Duchy of Athens|Athens]], which ends the conflict, on [[August 6]].
* [[August 10]] &ndash; [[Manfred, King of Sicily|Manfred]], son of the late Emperor [[Frederick II, Holy Roman Emperor|Frederick II]], is crowned king of [[Kingdom of Sicily|Sicily]] at [[Palermo]]. [[Pope Alexander IV]], who has an alliance with the Saracens, declares the coronation void and excommunicates Manfred.
* [[August 16]] &ndash; [[Theodore II Laskaris]] dies after a 4-year reign at [[Magnesia on the Maeander|Magnesia]]. He is succeeded by his 7-year-old son, [[John IV Laskaris|John IV]], as ruler of the [[Empire of Nicaea]]. His [[regent]] becomes the bureaucrat [[George Mouzalon]].<ref>Fine, John Van Antwerp (1994). ''The Late Medieval Balkans: A Critical Survey from the Late Twelfth Century to the Ottoman Conquest'', p. 161. Ann Arbor, Michigan: University of Michigan Press. {{ISBN|0-472-08260-4}}.</ref>
* [[August 25]] &ndash; George Mouzalon is assassinated in [[Magnesia ad Sipylum]], as part of a conspiracy led by Byzantine nobles, under future Emperor [[Michael VIII Palaiologos]].
* [[Gissur Þorvaldsson]], Icelandic chieftain (or [[Gothi|goði]]), is made Earl of [[Iceland]] for his loyal service to King [[Haakon IV of Norway]] ("the Old").