1263

By place

Byzantine Empire

• Before July - Battle of Settepozzi: A Byzantine-Genoese fleet is routed by the Venetians near Spetses in the Argolic Gulf, who capture four ships and inflict considerable casualties. Later, the Genoese that survive the battle managed to capture Chania on Crete. They receive orders to avoid direct confrontations with the Venetian fleet, but instead are engaged in raiding against the Venetian merchant convoys in the Euripus Strait.
• Summer - Emperor Michael VIII Palaiologos sends a Byzantine expeditionary force led by his half-brother, Constantine Palaiologos, to the Peloponnese in southern Greece. The army is transported to Monemvasia on Genoese ships, while a small Byzantine fleet is sent to harass the Latin island holdings in Euboea and the Cyclades. After arriving at Monemvasia, Constantine lays siege to Sparta, while the Byzantine fleet seizes the southern coast of Laconia.
• Battle of Prinitza: Constantine Palaiologos marches the Byzantine army up the rivers Eurotas and Alfeios towards the Achaean capital, Andravida. At a narrow pass at Prinitza in Elis, the Byzantines are attacked by Achaean forces under John of Katavas, who inflict a resounding defeat upon them; many Byzantine soldiers are killed. Constantine himself barely escapes with his life, and flees with the remainder of his army to the safety of Mystras.

Europe

• July - Scottish–Norwegian War: King Haakon IV of Norway assembles a fleet, and sets sail to defend the Hebrides, in an attempt to reassert Norwegian sovereignty over the Western Isles of Scotland. Haakon stops at the Isle of Arran, where in August negotiations are started with the 21-year-old King Alexander III of Scotland. The talks are prolonged by the Scots until the autumn storms begin.
• September 12 - Mindaugas, the only Christian king of Lithuania, is assassinated by his cousin Treniota. The country reverts to paganism and loses its status as a kingdom. Treniota usurps the throne.
• October 2 - Battle of Largs: Scottish forces under Alexander Stewart rout a Viking invasion force led by Haakon IV at Largs in North Ayrshire. The battle is inconclusive. On the morning of October 3, the Norwegians return to collect their dead and burn their beached ships. By the end of October, the Viking fleet reaches Orkney, where Haakon becomes ill and dies at the Bishop's Palace, on December 16.
• December - Magnus VI succeeds his father Haakon IV as Norway (872–1397)|King of Norway]. The chieftains of the eastern part of Iceland become the last to pledge fealty to Magnus, bringing a more complete end to the Icelandic Commonwealth and the Age of the Sturlungs.
• Winter - Reconquista: King Alfonso X of Castile conquers Niebla from the Moors, terminating any Muslim presence in the western region of Spain.
• Reconquista - King James I of Aragon captures Crevillent from the Moors and it becomes a part of the Kingdom of Valencia.

England

• April - Simon de Montfort, 6th Earl of Leicester, newly returned from exile, takes control of southern England. In early May he summons a meeting of rebel barons at Oxford.
• July 16 - Rebels occupy London.
• Baronial forces led by Robert de Ferrers and Henry de Montfort lay siege to Worcester. The attackers finally enter the city and are allowed to sack it. They kill most of the Jewish community as part of the History of the [Jews in England (1066–1290)#Targeting of Jews during the conflict with the Barons|targeting of Jews during the conflict with the Barons] by allies of de Montfort.
• October 2 - King Henry III of England travels to Boulogne for an attempt to broker peace with his barons by King Louis IX of France.

Levant

• April 4 - Egyptian forces led by Sultan Baibars attack Acre; there is severe fighting outside the walls, in which the seneschal, Geoffrey of Sergines, is badly wounded. Baibars is not yet ready to besiege the city and begins a major campaign to eliminate the Crusader kingdom of Jerusalem, the county of Tripoli and the principality of Antioch.

By topic

Arts and Culture

• The Savoy Palace is constructed in London by Peter II, Count of Savoy.

Education

• Presumed date - Balliol College is established in the University of Oxford by John I de Balliol on its modern-day site.

Markets

• The Lord Edward, son and heir of Henry III of England, seizes £10,000 which had been deposited to the trust of the Knights Templar in London by foreign merchants and English magnates.
• The Bonsignori firm gains the full market of the transfer of fiscal revenue from the papal estates to Rome.

Religion

• July 20–24 - Nahmanides, Spanish chief rabbi, defends the Talmud in an important debate against Pablo Christiani, before James I of Aragon.
• Probable date – The doctrines of Joachim of Fiore, French hermit and theologian, are condemned as heresy by the Catholic Church Synod of Arles.

Births

• January 22 - Ibn Taymiyyah, Syrian philosopher
• February 8 - Afonso of Portugal, Lord of Portalegre, Portuguese prince
• March 20 - Yolande of Dreux, queen consort of Scotland
• Henry III, German nobleman
• Ingeborg of Sweden, countess of Holstein-Plön
• Juliana FitzGerald, Lady of Thomond, Norman-Irish noblewoman
• Napoleone Orsini, Italian cardinal and diplomat
• Philip of Chieti, Flemish nobleman and knight
• Roseline of Villeneuve, French Carthusian nun and saint
• Theobald II, Duke of Lorraine, German nobleman
• Tolberto III da Camino, Italian nobleman and condottiero
• Zhongfeng Mingben, Chinese Buddhist master

Deaths

• January 7 - Agnes of Merania, duchess of Carinthia
• January 16 - Shinran, founder of Jōdo Shinshū
• March 19 - Hugh of Saint-Cher, French friar and bishop
• April 20 - John I, Count of Holstein-Kiel, German nobleman
• June 7 - Boniface, Savoyan nobleman
• September 12 - Mindaugas, king of Lithuania, assassinated
• November 14 - Alexander Nevsky, Grand Prince of Novgorod
• November 20 - Martino della Torre, Italian nobleman and condottiero
• December 16 - Haakon IV of Norway, king of Norway
• December 24 - Hōjō Tokiyori, Japanese nobleman
• Al-Ashraf Musa, Ayyubid prince and ruler of Homs
• Caesarius of Alagno, Italian priest, bishop and counsellor
• Gilbert I de la Hay, Scottish nobleman, knight and regent
• Guy I de la Roche, duke of Athens and Thebes
• John XIII bar Ma'dani, Syrian patriarch of Antioch
• Manuel I, emperor of Trebizond
• Senana ferch Caradog, Welsh noblewoman