Year 1311 (MCCCXI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.
March 15 – Battle of Halmyros: The Catalan Company defeats Walter V, Count of Brienne and his forces to take control of the Duchy of Athens.
October 16 - Beginning of the Council of Vienne.
A committee of 21 English barons draw up a series of ordinances, which substitute ordainers for the King (Edward II) as the effective government of the country.
Bolingbroke Castle passes to the House of Lancaster.
Completion of Lincoln Cathedral in England. With the spire reaching around 525 feet (160 m) it becomes the world's tallest structure (surpassing the Great Pyramid of Giza, which held the record for almost 4,000 years), a record it holds until the spire is blown down in 1549.
January 28 or 1312 – Joan II of Navarre, daughter of King Louis X of France (d. 1349)
June 24 or 1314 – Philippa of Hainault, queen of Edward III of England (d. 1369)
August 13 – King Alfonso XI of Castile (d. 1350)
July 1 – Liu Bowen, Chinese military strategist, officer, statesman and poet (d. 1375)
date unknown
Peter I, Duke of Bourbon (d. 1356)
Margaret II, Countess of Hainaut (d. 1356)
January 27 – Külüg Khan, Emperor Wuzong of Yuan
March 3 – Antony Bek, bishop of Durham
March 15 – at the Battle of Halmyros:
Walter V, Count of Brienne, Duke of Athens
Thomas III d'Autremencourt, Lord of Salona, Marshal of Achaea
Albert Pallavicini, Margrave of Bodonitza
George I Ghisi, Triarch of Euboea, Baron of Chalandritsa, Lord of Tinos, Mykonos, Serifos and Keos
May 29 – James II of Majorca (b. 1243)
August 13 – Pietro Gradenigo, Doge of Venice
date unknown
David VIII of Georgia (b. 1273)
Arnold of Villanova, Spanish alchemist and physician (b. 1235)
probable – Bernard Saisset, Occitan bishop of Pamiers (b. 1232)
1311 Wikipedia (Text) CC BY-SA