|Ab urbe condita||2035|
|Balinese saka calendar||1203–1204|
|English Regnal year||10 Edw. 1 – 11 Edw. 1|
|Chinese calendar||辛巳年 (Metal Snake)|
3978 or 3918
— to —
壬午年 (Water Horse)
3979 or 3919
|- Vikram Samvat||1338–1339|
|- Shaka Samvat||1203–1204|
|- Kali Yuga||4382–4383|
|Japanese calendar||Kōan 5|
|Minguo calendar||630 before ROC|
|Thai solar calendar||1824–1825|
1408 or 1027 or 255
— to —
1409 or 1028 or 256
- March 30 – War of the Sicilian Vespers: A group of Sicilian conspirators begins an uprising against the rule of King Charles I; over the next six weeks, thousands of French are killed. The rebellion forces Charles to abandon the Ninth Crusade, while still en route to the target city of Constantinople and allows King Peter III (the Great) to take over rule of the island from Charles (which in turn leads to Peter's excommunication by Pope Martin IV).
- May 1 – Battle of Forlì: A French expeditionary army under Jean d'Eppe launches an assault on Forlì and breaches the outer wall. While they plunder the suburbs, Guido I da Montefeltro sends a small force out the gate on the opposite side of the city. In an ambush, Guelph and Ghibelline forces defeat the main army of d'Eppe, who is forced to retreat to Faenza. He requests Martin IV for more reinforcements, but this is refused.
- Summer – A Aragonese expeditionary army under Peter III lands in North Africa in Collo, in proclaimed support of a rebellion of the governor of Constantine, Ibn Wazir. The revolt is suppressed by Abu Ishaq Ibrahim I, ruler of the Hafsid Sultanate. Peter, wary of the situation in Sicily, sails off and fails to take advantage of the state of rebellion in North Africa. Ibrahim stabilizes his power and styles himself emir of the sultanate.
- June – The 24-year-old Prince Sancho, heir to the throne of Castile, assembles a coalition of nobles and starts a massive rebellion against his father, King Alfonso X (the Wise). He dispatched his brothers into the realm to claim strategically important cities and castles. Only the cities of Seville, Murcia, and Badajoz remain loyal to Alfonso, who becomes isolated politically and abandoned by most of his family.
- June 26 – King Denis I (the Poet King) marries the 11-year-old Elizabeth of Aragon, daughter of Peter III (the Great), in Trancoso. Elizabeth received the towns of Óbidos, Abrantes, and Porto de Mós as part of her dowry. Denis, known for his poetry, writes several poems and books himself, with topics of administration and hunting. During his reign, Lisbon becomes one of Europe's centers of art and culture.
- July – Alfonso X (the Wise) allies himself with Abu Yusuf Yaqub ibn Abd al-Haqq, ruler of the Marinid Sultanate, who crosses the straits, and establishes a camp at Zahara de la Sierra, in southern Spain. Alfonso offers the Castilian royal crown of his father and grandfathers as a pledge of re-payment of a loan. Out of pity, Abu Yusuf gives him 100,000 gold dinars.
- August – Castilian forces under Sancho lay siege to Badajoz, who eventually retreat as the combined armies of Alfonso X (the Wise) relieve the city. Shortly after, Alfonso marches to Córdoba and demands the key of the city. This is refused by Diego López V de Haro, speaking on behalf of the magnates. Meanwhile, the Marinids plunder the Guadalquivir valley.
- August 30 – Peter III (the Great) traveling with his fleet on a military expedition against Tunis, ends up in the Sicilian town of Trapani, after he was asked by the inhabitants of Palermo to help in the fight against Charles I.
- September 4 – Peter III (the Great) is proclaimed "King of Sicily". Charles is forced to flee across the Strait of Messina, only to be content with the Kingdom of Naples (ruling a part of the Italian Peninsula with Martin IV).
- September or October – Battle of Lake Hód: Hungarian forces led by King Ladislaus IV successfully repel and defeat an invading Cuman army. Ladislaus receives for his heroic victory the title "the Cuman".
- November – Castilian forces under Alfonso X (the Wise) reconquer Córdoba. Pope Martin IV issues a papal bull, forcing Sancho and his nobles to proclaim their allegiance to Alfonso. Ending the rebellion.
- December 27 – King Rudolf I invests his sons, Albert I and Rudolf II, as co-rulers of the duchies of Austria and Styria, and lays the foundation of the House of Habsburg in these territories.
- Dutch forces led by Floris V, count of Holland, attack and defeat the West Frisians at the battle of Vronen. He succeeds in retrieving the body of his father, William II, some 26 years dead.
- King Stefan Dragutin breaks his leg while hunting and becomes ill. He abdicates the throne in favor of his younger brother, Stefan Milutin, who becomes ruler of Serbia (until 1321).
- Peter III (the Great) obtains the support of Nasrid Granada preparing for the incoming Aragonese Crusade, led by Philip the Fair of France.
- March – Welsh forces under Prince Dafydd ap Gruffydd, brother of Llywelyn ap Gruffudd, attack and take control of Hawarden Castle. The garrison is massacred and Constable Roger de Clifford is taken prisoner. Llywelyn who has sworn fealty to King Edward I (Longshanks), joins Dafydd in his revolt against the English. Their actions lead to the final English conquest of Wales, by Edward.
- June 17 – Battle of Llandeilo Fawr: English forces led by Gilbert de Clare are ambushed and defeated by Welsh troops at Llandeilo. English expansion into southern Wales is halted.
- November 6 – Battle of Moel-y-don: English forces led by Luke de Tany are ambushed and defeated by Welsh troops, while crossing over a floating bridge to the island of Anglesey.
- December 11 – Battle of Orewin Bridge: English forces (some 6,000 men) under Edward I (Longshanks) defeat a Welsh army near Cilmeri. Llywelyn ap Gruffudd is killed.
- The form for the Trial of the Pyx, during which it is confirmed that newly minted coins conform to required standards, is established.
- The first evidence is discovered of the existence of consolidated public debt in Bruges, confirming the expansion of use of annuities, to fund government expenditure to the Low Countries.
- February 2 – Maud Chaworth, English noblewoman (d. 1322)
- April 1 – Louis IV (the Bavarian), Holy Roman Emperor (d. 1347)
- April 15 – Frederick IV (the Fighter), German nobleman (d. 1329)
- May 5 – Juan Manuel, Spanish nobleman and prince (d. 1348)
- June 19 – Gwenllian ferch Llywelyn, princess of Wales (d. 1337)
- August 7 – Elizabeth of Rhuddlan, English princess (d. 1316)
- Alexios II (Megas Komnenos), emperor of Trebizond (d. 1330)
- Annibale di Ceccano, Italian cardinal and archbishop (d. 1350)
- Blanche of France, French princess (House of Capet) (d. 1305)
- Clare of Rimini, Italian noblewoman, nun and saint (d. 1346)
- Eric Magnusson, Swedish prince and heir apparent (d. 1318)
- Konoe Iehira, Japanese nobleman (Fujiwara Clan) (d. 1324)
- Li Shixing (or Zhun Dao), Chinese landscape painter (d. 1328)
- Nicholas Kőszegi, Hungarian prelate and bishop (d. 1336)
- Oshin, king of Cilician Armenia (House of Lampron) (d. 1320)
- Özbeg Khan, Mongol ruler of the Golden Horde (d. 1341)
- Paolo Dagomari di Prato, Italian mathematician (d. 1374)
- Spinetta Malaspina (the Great), Italian nobleman (d. 1352)
- January 8 – Hōjō Yoshimasa, Japanese nobleman (b. 1243)
- February 22 – Guiscardo Suardi, Italian prelate and bishop
- February 24 – Philippe Mouskes, French bishop and writer
- March 2 – Agnes of Bohemia, Bohemian princess (b. 1211)
- March 22 – Benvenutus Scotivoli, Italian priest and bishop
- April 4
- April 10 – Ahmad Fanakati, Persian minister and politician
- April 26 – Möngke Temür, Mongol ruler of Shiraz (b. 1256)
- April 29 – Guillaume de Bray, French prelate and cardinal
- May 16 – Thomas III, Savoyan nobleman (House of Savoy)
- June 19 – Eleanor de Montfort, princess of Wales (b. 1252)
- August 25 – Thomas de Cantilupe, English bishop (b. 1218)
- September 9 – Ingrid of Skänninge, Swedish noblewoman
- October 13 – Nichiren, Japanese Buddhist priest (b. 1222)
- October 27 – Roger Mortimer, English nobleman (b. 1231)
- October 30 – Ibn Khallikan, Barmakid historian (b. 1211)
- November 6
- December 11
- December 17 – Wichard of Pohlheim, German bishop
- Alice de la Roche, Outremer noblewoman and regent
- Benedetto Sinigardi, Italian Franciscan friar (b. 1190)
- George Akropolites, Byzantine historian and statesman
- Hugh de Benin (or Benhyem), Scottish cleric and bishop
- Isabella of Ibelin, Outremer noblewoman (House of Ibelin)
- Margaret Sambiria, Danish queen and regent (b. 1230)
- Robert IV, French nobleman (House of Dreux) (b. 1241)
- Robert de Neville, English nobleman and knight (b. 1223)
- Kleinherz, Christopher (2004). Medieval Italy: An Encyclopedia, p. 473. Routledge.
- Meynier, Gilbert (2010). L'Algérie cœur du Maghreb classique. De l'ouverture islamo-arabe au repli (658-1518). Paris: La Découverte. p. 163. ISBN 978-2-7071-5231-2.
- Joseph F. O'Callaghan (2011). The Gibraltar Crusade: Castile and the Battle for the Strait, p. 82. ISBN 978-0-8122-2302-6.
- Joseph F. O'Callaghan (2011). The Gibraltar Crusade: Castile and the Battle for the Strait, p. 83. ISBN 978-0-8122-2302-6.
- Chaytor, H.J. (1933). A History of Aragon and Catalonia, p. 103. London: Methuen. ISBN 978-0-404-01479-7.
- Harris, Jonathan (2003). Byzantium and the Crusades, p. 180. London: Hambledon. ISBN 978-1-85285-298-6.
- Berend, Nora (2001). At the Gate of Christendom: Jews, Muslims and "Pagans" in Medieval Hungary, c. 1000–c.1300. Cambridge University Press. p. 147. ISBN 978-0-521-02720-5.
- Hywel Williams (2005). Cassell's Chronology of World History, p. 149. ISBN 0-304-35730-8.
- Lourie, Elena (2004). Jews, Muslims, and Christians in and around the Crown of Aragon: essays in honour of Professor Elena Lourie. Brill. p. 295. ISBN 90-04-12951-0. Archived from the original on November 7, 2016. Retrieved October 13, 2016.
- Morris, Marc (2008). A Great and Terrible King: Edward I and the Forging of Britain, p. 180. London: Hutchinson. ISBN 978-0-09-179684-6.
- Prestwich, Michael (1997). Edward I, pp. 191–92 (updated ed.). New Haven: Yale University Press. ISBN 0-300-07209-0.
- Zuijderduijn, Jaco (2009). Medieval Capital Markets. Markets for renten, state formation and private investment in Holland (1300-1550). Leiden/Boston: Brill. ISBN 978-90-04-17565-5.
- Lock, Peter (2013). The Routledge Companion to the Crusades. Routledge. p. 120. ISBN 9781135131371.