'Sfagí tón Latínon') was a large-scale massacre of the mainly Italian Roman Catholic (called " Latin") inhabitants of Constantinople, the capital of the Byzantine Empire, by the Eastern Orthodox population of the city in April 1182.

[1] Following the death of Manuel I in 1180, his widow, the Latin princess Maria of Antioch, acted as regent to her infant son Alexios II Komnenos.

Her regency was notorious for the favoritism shown to Latin merchants and the big aristocratic land-owners, and was overthrown in April 1182 by Andronikos I Komnenos, who entered the city with a wave of popular support.

[5] Latin clergymen received special attention, and Cardinal John, the papal legate, was beheaded and his head was dragged through the streets at the tail of a dog.

[15] Andronikos had managed to incite the anti-Latin sentiment of Constantinopolitans, on the grounds that the empress and the protosebastos had bought Latin support by promising them the chance of plundering the city.

The massacre further worsened the reputation of the Byzantines in the West, and although regular trade agreements soon resumed between Byzantium and Latin states, the underlying animosity would remain, leading to a spiraling chain of hostilities: a Sicilian expedition under William II of Sicily in 1185 sacked Thessalonica, the Empire's second largest city, and the German emperors Frederick Barbarossa and Henry VI both threatened to attack Constantinople.

[17] The worsening relationship culminated with the brutal sack of the city of Constantinople by the Fourth Crusade in 1204, which led to the permanent alienation of Eastern Orthodox and Roman Catholics.