Year 1277 (MCCLXXVII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire March 19 – Byzantine–Venetian Treaty: Emperor Michael VIII (Palaiologos) concludes an agreement with the Republic of Venice. Stipulating a two-year truce, and renewing Venetian commercial privileges in the Byzantine Empire. Michael keeps the Venetians and their fleet from participating in the attempts of Charles I, king of Sicily, to organize an anti-Byzantine crusade, while the Venetians can retain their access to the Byzantine market. Battle of Pharsalus: Michael VIII (Palaiologos) sends a Byzantine expeditionary army under John Synadenos to invade Thessaly. The Byzantines are ambushed and defeated by Greek forces under John I (Doukas), Latin ruler of Thessaly, near Pharsalus (or Old Pharsalus). During the battle, Synadenos is captured and Michael Kaballarios, commander of the Latin mercenaries, dies shortly afterward of his wounds. Summer – Uprising of Ivaylo: A uprising under Ivaylo breaks out in northeastern Bulgaria against Emperor Constantine I Tikh to cope with the constant Mongol invasions which devastated the country for years. He confronts and defeats the plundering Mongols, and by autumn all Mongols are driven out of Bulgarian territory. In return, Constantine gathers a small army and tries unsuccessfully to suppress the revolt. Europe January 21 – Battle of Desio: Lombard forces under Archbishop Ottone Visconti defeat the Della Torre family troops for the rule of Milan. Later, Ottone enters the city in triumph, and imprisons Napoleone della Torre in the Castello Baradello at Como (Northern Italy). March – Siger of Brabant, Dutch teacher and philosopher, is condemned by the French Inquisition for his advocacy of the Averroist doctrine that reason is separate from Christian faith. March 18 – Charles I, king of Sicily, buys the title to the Kingdom of Jerusalem from Maria of Antioch, for 1,000 bezants and an annual payment of 4,000 livres tournois. May 12 – Mehmet I of Karaman, Seljuk vizier, issues a firman (decree) ordering the Turkish language to be used, instead of Arabic or Persian in government offices. August – Marinid forces led by Sultan Abu Yusuf cross the Strait of Gibraltar and marches north, ravaging the districts of Jerez de la Frontera, Seville and Córdoba. England November 10 – Treaty of Aberconwy: Prince Llywelyn ap Gruffudd and Edward I (Longshanks) sign a peace treaty which leaves Llywelyn only with the western part of