Originally intended to reclaim Jerusalem, the Fourth Crusade was diverted from its primary objective in the eastern Mediterranean. Instead of reaching the Holy Land, the crusading forces arrived at Constantinople in 1204, where they besieged and ultimately sacked the capital of the Byzantine Empire.

The assault on this major Christian city marked a pivotal and controversial moment in medieval history. The event had profound implications for the region, resulting in significant political instability and the temporary collapse of Byzantine authority. Key consequences of the sack included:

• The violent looting of the city's wealth and religious relics.
• A permanent deepening of the schism between Eastern Orthodox and Roman Catholic Christianity.
• The establishment of the short-lived Latin Empire in Constantinople.
• A lasting weakening of the Byzantine state, which left it vulnerable to future territorial losses.

The fall of the city to western forces fundamentally altered the trajectory of the Crusades and left a legacy of bitterness that persisted for centuries. By prioritising political and economic interests over their original religious mandate, the crusaders irrevocably damaged the relationship between the Latin West and the Greek East.