The Byzantine Empire was heavily dependent on trade with the East, and the rise of Muslim power in the region threatened these trade routes.

Alexios I Komnenos sought the aid of Western European knights to help him repel the Seljuk Turks, who had captured much of Anatolia.

The Byzantine Empire was able to retake several cities and regions in Anatolia that had been lost to the Seljuk Turks.

Theodora Komnene was the daughter of Emperor Alexios I Komnenos and Empress Irene Doukaina.

Manuel I Komnenos sought to bridge the gap between the Eastern Orthodox and Roman Catholic churches, but his efforts ultimately failed.

The Fourth Crusade had a devastating impact on the Byzantine Empire, leading to its capture and sack by Western European forces and the establishment of a Latin Empire in Constantinople.

Michael VIII Palaiologos recaptured Constantinople from the Latins in 1261 and restored the Byzantine Empire.

The Byzantine Empire faced a combination of economic, political, and military challenges after the Crusades, which ultimately led to its decline.

Andronikos III Palaiologos attempted to revive the Byzantine Empire by reconquering lost territories and reforming the government, but his efforts were ultimately unsuccessful.

The Byzantine Empire fell to the Ottoman Turks in 1453, marking the end of the Byzantine Empire and the beginning of Ottoman rule.

The Crusades often led to tensions and conflicts between the Byzantine Empire and the Western European states, particularly during the Fourth Crusade, which resulted in the capture and sack of Constantinople.

John V Palaiologos sought to strengthen ties with the West and modernize the Byzantine military in an attempt to repel the Ottoman threat.

Constantine Palaiologos, the last Byzantine emperor, led the defense of Constantinople against the Ottoman siege in 1453.

The fall of Constantinople in 1453 marked the end of the Byzantine Empire, led to the establishment of the Ottoman Empire, and resulted in the spread of Greek culture and learning to Western Europe.

France played a significant role in the Fourth Crusade, with many French knights and nobles participating in the expedition.