Editing 1266 (section)

== Deaths ==
* [[January 2]] &ndash; [[Simon Walton (bishop)|Simon de Walton]], English cleric and bishop
* [[January 11]] &ndash; [[Swietopelk II, Duke of Pomerania]] ("the Great"), Polish nobleman
* [[February 12]] &ndash; [[Walter de Cantilupe]], English bishop (b. [[1195]])
* [[February 26]]
** [[Manfred, King of Sicily]], illegitimate son of Frederick II, Holy Roman Emperor (b. [[1232]])<ref>{{cite web|title=Manfred - king of Sicily|url=https://www.britannica.com/biography/Manfred-king-of-Sicily|website=Encyclopedia Britannica|access-date=27 April 2018|language=en}}</ref>
** [[Richard of Lauria]], Italian nobleman and [[Condottiero|condottiere]]
* March &ndash; [[Margaret de Quincy, Countess of Lincoln]], English noblewoman and heiress
* [[April 14]] &ndash; [[Roger of Torre Maggiore]], Italian archbishop 
* [[May 7]] &ndash; [[Fariduddin Ganjshakar]], Ghurid preacher (b. [[1179]])
* [[May 27]] &ndash; [[Elisabeth of Brunswick-Lüneburg]], queen consort of the Romans, Countess of Holland and Countess of Zeeland (b. [[1230]])
* [[June 12]] &ndash; [[Henry II, Prince of Anhalt-Aschersleben]], German nobleman (b. [[1215]])
* [[July 24]] &ndash; [[Albrecht von Mutzschen|Albrecht II of Meissen]], German [[Canon (priest)|canon]] and bishop
* [[August 4]] &ndash; [[Odo, Count of Nevers]] (Odo or Eudes of Burgundy), French nobleman 
* [[August 8]] &ndash; [[Sayyed Ibn Tawus]], Abbasid theologian (b. [[1193]])
* [[September 20]] &ndash; [[Jan Prandota]], bishop of [[Roman Catholic Archdiocese of Kraków|Kraków]] (b. [[1200]])
* [[October 21]] &ndash; [[Birger Jarl]], Swedish nobleman and knight (b. [[1210]])
* [[October 28]] &ndash; [[Arsenije Sremac]], Serbian disciple and archbishop 
* [[October 29]] &ndash; [[Margaret of Austria, Queen of Bohemia|Margaret of Austria]], queen consort of [[Kingdom of Germany|Germany]] and later of Bohemia (b. [[1204]])
* [[November 19]] &ndash; [[Nasiruddin Mahmud Shah, Sultan of Delhi|Nasiruddin Mahmud Shah]], Mamluk ruler of [[Delhi Sultanate|Delhi]]
* [[December 3]] &ndash; [[Henry III the White]]), duke of [[Duchy of Silesia|Silesia]]-[[Wrocław]]
* December &ndash; [[John of Ibelin (jurist)|John of Ibelin]] ("John of Jaffa"), Outremer nobleman, crusader knight and legal writer (b. [[1215]])
* [[Aldonza Alfonso de León]], illegitimate daughter of [[Alfonso IX of León|Alfonso IX]]
* [[Andronikos II of Trebizond|Andronikos II]] (''Megas Komnenos''), emperor of [[Empire of Trebizond|Trebizond]]
* [[Ariq Böke]] (or Bukha), Mongol ruler (''[[khagan]]'') and [[regent]]
* [[Berke|Berke Khan]], Mongol ruler of the [[Golden Horde]] (b. [[1208]])
* [[Chen Rong (painter)|Chen Rong]], Chinese painter, poet and politician (b. 1200)
* [[Hugh Bigod (Justiciar)|Hugh Bigod]], English nobleman and chief justiciar (b. [[1211]])
* [[Hugh, Count of Burgundy]] (Hugh III of Châlon), French nobleman and knight (b. [[1220]])
* [[Luca Savelli]], Italian senator and politician (b. [[1190]])
* [[Máel Coluim II, Earl of Fife|Máel Coluim II, Mormaer of Fife]] (Malcolm II, Earl of Fife), Scottish nobleman<ref>{{cite web|title=Malcolm (II), earl of Fife (d.1266)|url=http://db.poms.ac.uk/record/person/2129/|website=db.poms.ac.uk|access-date=27 April 2018}}</ref>
* [[Mu'ayyad al-Din al-Urdi]], Syrian scholar and astronomer
* [[Philippe Chinard]], French nobleman and admiral, murdered (b. [[1205]])
* [[Richer of Senones]], French monk and chronicler (b. 1190)