The Byzantine Empire was one of the world's longest lasting empires with a lifespan of over 1,100 years. It was founded in 330 AD with the establishment of Constantinople as the Roman Empire's new capital and ended when Constantinople fell to the Ottomans in 1453.

The Byzantine Empire was actually the Roman Empire itself continued throughout the Middle Ages. Rome did not fall in 476 AD, rather it continued to survive for a thousand more years in the east with Constantinople as its capital. True enough, the Byzantines never called themselves "Byzantines" but "Romans" and their empire as the "Roman Empire".  The word "Byzantine" was only coined in the 16th century when the empire had already fallen.  

The Byzantines were the keepers and protectors of most of ancient history. All while the rest of Europe was in the "dark ages", the Byzantines preserved Classical knowledge of Ancient Greece and Rome which would be vital in kickstarting the Renaissance in Europe. Byzantine scholars in the 15th century true enough brought this said knowledge west to Italy and to the rest of Europe as the Byzantine Empire had fallen. Additionally, the Byzantines were known to have had a notable female historian being Anna Komnene from the 12th centiury. 

In its lifetime of over 1,100 years (330-1453 AD), the Byzantines had a total of 90 emperors and 15 ruling dynasties. Some of the most influential Byzantine emperors include Justinian I the Great (r. 527-565) whose reign saw the Byzantines reconquer the lost Roman provinces of Italy, Africa, and Southern Spain; and Basil II (r. 976-1025) who is best remembered as Byzantium's longest ruling emperor. 

Interestingly, the Byzantines invented the fork and introduced it to Europe in the 10th century through an imperial marriage between the Byzantine princess Theophano and the future Holy Roman emperor Otto II.

The Byzantines were partly responsible for starting the Crusades in the late 11th century as the crushing Byzantine defeat to the Seljuk Turks at the Battle of Manzikert in 1071 AD had led to the Byzantine emperor Alexios I Komnenos to call for an armed movement from Europe to take back lost territories, however this movement became the First Crusade which had its own objectives rather than just simply coming to Byzantium's rescue.  

The Byzantine capital Constantinople was captured by Crusaders as part of the 4th Crusade in 1204. For 57 years, the Crusaders occupied Constantinople until the Byzantines took back their capital by surprise in 1261. 

Constantinople's city walls were so difficult to besiege that no army ever succeeded in breaching it until the Ottomans in 1453 due to the invention of the cannon. Constantinople fell to the Ottomans in 1453 which therefore ends the Byzantine Empire's story. However, the Byzantines had break-away states with one being the Empire of Trebizond created in 1204 after the fall of Constantinople to the Crusaders. The fall of Trebizond in 1461 is therefore considered by some to be the real end of the Byzantine Empire. 

Most of Eastern European/ Slavic culture and history is fundamentally based on Byzantine culture. It was the Byzantines that true enough converted the Slavs and most Eastern Europeans to Orthodox Christianity while the Cyrillic Alphabet which is commonly used by most Eastern European countries too was a contribution of the Byzantines.