In 1204, western crusaders infamously sacked Constantinople. Historians and pundits continue to focus on this event to this day. However, a Byzantine massacre of Catholics a couple decades earlier is forgotten or ignored. The Massacre of the Latins took place in Constantinople with the emperor's blessing. The event further strained relations between eastern and western Christianity and helped lead to the 1204 attack.
The Venetians arrived in Constantinople in the 11th century. They managed to win trade concessions from the Byzantine emperor Alexios I Komnenos. Other European merchants followed. The Europeans established "Latin quarters" within the city to ply their trade. However, the Byzantine people resented the Latin influence.
Latin dominance over commerce decimated native businesses. At the same time, it helped strengthen and expand aristocratic power in the city. As a result, the Byzantine middle and lower orders grew to resent the Latins. In their view, the foreigners destroyed their economic opportunities, made life more difficult, and were arrogant. The charge of arrogance might be the result of cultural differences between the Italians and Byzantines. Interestingly, native populations around the world and throughout time often make the same arguments about successful immigrants and foreigners within their borders.
In addition to economic and cultural differences, religion helped separate the two populations. The eastern and western church split over religion, iconography, some doctrine, and language. Both Rome and Constantinople claimed European religious preeminence. These differences became deeply rooted and were exacerbated when the Venetians and Byzantines went to war. The two sides agreed to a truce in 1179 after stalemate. Meanwhile, other Italian city states experienced windfall profits in the war.
By 1180, 60,000 Latins lived in Constantinople. The Byzantine people despised the merchants for their alleged transgressions and for the war. Emperor Manuel I died that year leaving his infant son's regent to rule. Regent Maria of Antioch supported the Latins. As a result, Andronikos I Komnenos led a successful coup against the regency in 1182. The city celebrated their "liberation" from an unpopular administration. In short order, the celebrations turned violent as mobs began to invade the Latin quarter. They murdered Catholics indiscriminately. Men, women, children, old, young, and infirm were all butchered. The mob murdered people in their hospital beds and beheaded a papal legate. Churches and homes were ransacked and pillaged. The new emperor did nothing to stop the bloodshed.
Many Latins fled Constantinople before the massacre. They could tell which way the winds were blowing. However, the Greeks still managed to kill tens of thousands of Catholics. The exact total is unknown. Relations between the west and Byzantine Empire hit its nadir. In response, William II of Sicily sacked the empire's second largest city while Frederick Barbarossa threatened invasion. A few years later, the dissatisfied Greeks turned Andronikos over to the Latins for torture and execution. In 1204, the west experienced a measure of revenge when crusaders sacked Constantinople itself. Often times, the crusaders are described as greedy mercenaries hungry for plunder. Although there is a measure of truth to this, it is unlikely the incident would have occurred if not for the Massacre of the Latins.
The Massacre of the Latins in 1182 led to the sacking of Constantinople by the crusaders. Cultural, religious, and economic differences between Latins and Greeks led to tensions within the city. Eventually, Andronikos' coup provided the opportunity for the Greeks to express their displeasure with Latin commerce. Tens of thousands died in the event, which reinforced western attitudes toward the Byzantines. In the end, the Massacre of the Latins provided the impetus for the 1204 crusader assault that the Byzantine Empire never recovered from.