1287

By place

Europe

• January 17 - Aragonese forces led by King Alfonso III conquer the island of Menorca. He signs the "Treaty of San Agayz" with Sultan Abû 'Umar ibn Sa'îd on January 21. Alfonso accepts a policy of free trade for merchants and their property. He also concludes an alliance against the Marinids with Abu Said Uthman I, ruler of the Zayyanid Kingdom of Tlemcen. He proposes to supply him with five to ten galleys in exchange for 500 elite Zayyanid horsemen.
• Alfonso III is forced to make concessions to the nobility after an aristocratic uprising. In particular, he grants his barons a "Bill of Rights", known as the Privilegium Generale. This leaves a heritage of disunity and further dissent among the nobility, who increasingly see little reason to respect the throne, and brings the Crown of Aragon to the point of anarchy. Alfonso, who is not pleased with the anti-royalist movement, is forced to accept the Magna Carta.
• June - Rabban Bar Sauma, Chinese Nestorian monk and diplomat, travels from Constantinople to [Kingdom of Kingdom of Italy (Holy Roman Empire)|Italy (Holy Roman Empire)|Italy]. There he arrives in Naples and witnesses a sea battle in the harbour between the Aragonese and the Angevin fleets. Bar Sauma goes to Rome, but arrives too late to meet Pope Honorius IV, who recently died. He instead is engaged in negotiations with the cardinals, who are in a conclave to elect a successor, and visits the St. Peter's Basilica. Bar Sauma goes to Genoa, where he receives a warm welcome.
• June 23 - Battle of the Counts: An Aragonese-Sicilian fleet under Admiral Roger of Lauria defeat a larger Angevin fleet of 70 galleys near Naples. After a feigned retreat, Roger attacks the Angevin galleys from all sides. During the battle, which last much of the day, the Angevin fleet is scattered, leaving about 40 galleys to be captured, along with 5,000 prisoners. After the victory, without any authorization from King James II, Roger makes a truce with the Neapolitans.
• September - Rabban Bar Sauma arrives in Paris, and is received in an audience by King Philip IV. He spends one month at the royal court, during his stay, Philip himself escorts him around the Sainte-Chapelle to see the collection of Passion relics by late King Louis IX. Philip gives Bar Sauma many presents and sends one of his noblemen, Gobert de Helleville, to return with him to Mongol lands. In response, he attempts to form a military alliance with France and England.
• December 14 - A huge storm and associated storm tide in the North Sea and English Channel, known as St. Lucia's flood in the Netherlands, kills thousands and reshapes the coastline of the Netherlands and England. In the Netherlands, a fringing barrier between the North Sea and a shallow lake collapses, causing the fifth-largest flood in recorded history – which creates the Zuider Zee inlet, and kills over 50,000 people. It also gives sea access to Amsterdam, allowing its development as an important port city.
• Winter - Mongol invasion of Poland: Mongol forces under Talabuga Khan and Nogai Khan, attack Poland for the third time. The cities of Lublin, Sandomierz and Sieradz are devastated by the invaders. Nogai Khan besieges Kraków and launches an unsuccessful assault on the fortified city, suffering heavy casualties in the process.

England

• February - South England flood: A large storm hits the south coast, this has a powerful effect on the Cinque Ports, two of which are hit. The storm destroys Old Winchelsea on Romney Marsh and nearby Broomhill. The course of the Rother River is diverted away from New Romney, which is almost destroyed, ending its role as a port; the Rother runs instead to the sea at Rye – whose prospects as a port are enhanced. A cliff collapses at Hastings, ending its role as a trade harbor and demolishing a part of Hastings Castle. New Winchelsea is established on higher ground.
• June 8 - Welsh forces led by Rhys ap Maredudd revolt in Wales against King Edward I. Although Maredudd has assisted the English in the past, he accuses Edward of treating him unfairly over taxes. The rebels burn several towns, including Swansea and Carmarthen. They capture most of Ystrad Tywi, heartland of Deheubarth.
• Summer - Edward I replies to the Welsh rebellion by raising an army at Gloucester commanded by Edmund of Almain. The English forces besiege Dryslwyn Castle, which lasts for three weeks before the castle falls after the curtain walls are undermined. Rhys ap Maredudd manages to escape and goes into hiding before the stronghold is finally captured in late September.
• December - Parts of Norfolk are flooded, the port of Dunwich in Suffolk is further devastated, and in The Fens through the storm and the violence of the sea, the monastery of Spalding and many churches are overthrown and destroyed: "The whole country in the parts of Holland was, for the most part, turned into a standing pool so that an intolerable multitude of men, women and children were overwhelmed with the water, especially in the town of Boston, a great part thereof was destroyed."

Middle East

• Spring - Arghun Khan, Mongol ruler of the Ilkhanate, sends an embassy under Rabban Bar Sauma with the mission of contracting a military alliance against the Mamluk Sultanate and take the city of Jerusalem. He travels with a large retinue and 30 riding animals from Tabriz through Armenia to Trebizond. Bar Sauma arrives in Constantinople and receives an audience with Emperor Andronikos II.
• March - Mamluk forces under Sultan Qalawun capture Latakia, last remnant of the Principality of Antioch. The city port falls easily into his hands, but the defenders retire to the citadel at the mouth of the harbour. Finally, Qalawun forces the Crusader garrison to surrender on April 20.
• October 19 - Bohemond VII, ruler of Tripoli, dies childless. He is succeeded by his sister Lucia, who is married to Charles I of Naples' former Grand Admiral, Narjot de Toucy. But the nobles, not pleased with this decision, offer the county to Bohemond's mother, Dowager-Princess Sibylla of Armenia.
• Winter - Two unidentified 'merchants' travel from Alexandria to Cairo to warn Qalawun of the economic dangers posed by Genoese domination in the eastern Mediterranean, which leaves the Mamluk trade at their mercy. Qalawun accepts the invitation to intervene, and breaks the truce with Tripoli.

Africa

• An Aragonese fleet raids the Tunisian Kerkennah Islands in the Gulf of Gabès.

Asia

• January 30 - Wareru creates the Hanthawaddy kingdom following the collapse of the Pagan Kingdom. He is crowned king on April 5 and declares himself independent of Pagan.
• May 14 - Nayan, Mongol prince of the Borjigin clan, revolts against the rule of Kublai Khan. Kublai leads a punitive expedition against Nayan in Manchuria and defeats his forces on July 16.
• December - Battle of Pagan: Mongol-led Yuan forces led by Temür Khan defeat King Thihathu of the Pagan Kingdom. The kingdom disintegrates and anarchy ensues.
• Kings Mangrai of the Lanna Kingdom and Ram Khamhaeng of the Sukhothai Kingdom agree to a peace treaty. They establish a "strong pact of friendship".

By topic

Art and Culture

• The Altar of St. James in Pistoia Cathedral, Italy - a masterwork of the silversmithing trade containing nearly a ton of silver - is begun; it will not be completed for nearly 200 years.

Economy

• The Italian city of Siena exacts a forced loan from its taxpayers for the first time, a common feature of medieval public finance.

Religion

• March 16 - Synod of Würzburg: A church council is held by Cardinal Giovanni Boccamazza and King Rudolf I at Würzburg. During the assembly, Giovanni announces the taxation of the clergy to finance the expedition of Rudolf to Rome and the imperial coronation.
• April 3 - Pope Honorius IV dies after a 2-year pontificate at Rome. During his reign, he tries to restore Sicily to papal vassalage, but Honorius clashes with King Peter III, who supports Sicilian independence.
• Construction of Uppsala Cathedral in Sweden begins.