In 600, the Byzantine Empire was one of the top powers in the Mediterranean and the Middle East, second only to the Persian Empire. However, between 600 and 750, the Byzantine Empire went through a severe decline. Read on to discover more about the sudden reversal of fortunes and the fall of the Byzantine Empire during this period.
Fall of the Byzantine Empire: Map
At the start of the seventh century, the Byzantine Empire (purple) stretched around the Northern, Eastern, and Southern coasts of the Mediterranean. To the east lay the Byzantines' main rival: the Persian Empire, ruled by the Sassanids (yellow). To the south, in North Africa and the Arabian Peninsula, various tribes dominated the lands beyond Byzantine control (green and orange).
Persian/Sasanian Empire
The name given to the Empire to the east of the Byzantine Empire was the Persian Empire. However, sometimes it is also referred to as the Sasanian Empire since this empire was ruled by the Sassanid dynasty. This article uses the two terms interchangeably.
Compare this to the following map showing the state of the Byzantine Empire in 750 C.E.
As you can see, the Byzantine Empire shrank considerably between 600 and 750 C.E.
The Islamic Caliphate (green) conquered Egypt, Syria, the Levant, the coast of North Africa, and the Iberian Peninsula in Spain from the Byzantine Empire (orange). Furthermore, because Byzantine troops had to deal with the Muslims and the Sassanids on their Southern and Eastern borders, they left the empire's Northern and Western borders open to attack. This meant that Slavic communities took over Byzantine territories near the Black Sea. The Byzantine Empire also lost territories formally held in Italy.
Caliphate
A political and religious Islamic state ruled by a caliph. Most caliphates were also transnational empires ruled by the Islamic ruling elite.
However, it is essential to note that the Byzantine Empire did manage to hold on to its capital of Constantinople throughout this period of military defeats. Although both the Sassanids and the Muslims attempted to take Constantinople, the city always remained in Byzantine hands.
Constantinople and the Byzantine Empire
When Emperor Constantine reunited the divided Roman Empire, he decided to move his capital from Rome to a different city. He chose the city of Byzantium for its strategic importance on the Strait of Bosporus and renamed it Constantinople.
Constantinople proved to be a practical choice for the Byzantine capital. It was mostly surrounded by water, which made it easily defendable. Constantinople was also closer to the centre of the Byzantine Empire.
However, Constantinople had a serious weakness. It was hard to get drinking water into the city. To deal with this problem, the Byzantine population built aqueducts into Constantinople. This water was stored in the impressive Binbirderek Cistern, which you can still see if you visit Constantinople today.
Today, Constantinople is known as Istanbul and is located in modern-day Turkey.
Fall of the Byzantine Empire: Reasons
Why did a mighty Empire's fortunes turn from glory to decline so quickly? There are always complex factors at play, but with the Byzantine decline, one reason stands out: the cost of constant military action.
Fig. 3 Plaque showing the Byzantine Emperor Heraclius receiving the submission of the Sassanid king Khosrau II. The Byzantines and Sassanids were constantly at war during this period.
The Cost of Constant Military Action
The empire was constantly at war with its neighbours for the entire century from 532 through to 628, when the Islamic Empire began to conquer Byzantine lands. The last and most crushing war, before its decline at the hands of the Islamic Arabs, came with the Byzantine-Sasanian war of 602-628. Although the Byzantine troops finally emerged victorious in this war, both sides exhausted their financial and human resources. The Byzantine treasury was depleted, and they were left with meagre manpower in the Byzantine army. This made the Empire vulnerable to attack.
Weak Leadership
The death of Byzantine Emperor Justinian I in 565 plunged the Empire into a crisis of leadership. It ended up being run by several weak and unpopular rulers, including Maurice, who was murdered in a revolt in 602. Phocas, the leader of this revolt, became the new Byzantine Emperor. Still, he had a reputation as a tyrant and faced many assassination plots. Only when Heraclius became the Byzantine Emperor in 610 did the Empire return to stability, but the damage had already been done. The Empire lost significant territory throughout this chaotic period, including the Balkans, Northern Italy, and the Levant.
Plague
The Black Death spread across the Empire during the 540s, decimating the Byzantine population. This was known as the Plague of Justinian. It wiped out much of the Empire's farming population and left little manpower for military action. Some historians believe that as many as 60% of Europe's population died during this plague outbreak, and Jeffrey Ryan argues that 40% of Constantinople's population perished due to the plague.1
The Plague of Justinian
We do not have the sources to know exactly how many people died during the Plague of Justinian. Historians who come up with high estimates tend to rely on qualitative, literary sources from the time. Other historians critique this approach because it relies too much on literary sources when there are economic and architectural sources that refute the idea that the plagues decimated the area nearly as severely as most people think.
For example, Mark Whittow points out that a considerable amount of silver dated to the latter half of the sixth century and that impressive buildings continued to be built in Byzantine lands.2 This does not seem to show a society on the brink of collapse due to plague, but rather that Byzantine life continued fairly normally despite the disease outbreak. The view that the plagues were not nearly as bad as historians usually think is called a revisionist approach.
Qualitative Data
Information that cannot be objectively counted or measured. Qualitative information is, therefore, subjective and interpretive.
Fall of the Byzantine Empire: Timeline
The Byzantine Empire lasted a long time, from its inception at the end of the Roman Empire to when the Ottomans conquered Constantinople in 1453. However, the Empire did not remain a constant force during this period. Rather, Byzantine fortunes rose and fell in a cyclical pattern. We are focusing here on the Empire's first rise under Constantine and Justinian I, followed by its first period of decline when the Islamic Caliphate conquered many Byzantine lands.
Let's take a closer look at the first rise and fall of the Byzantine Empire in this timeline.
| Year | Event |
| 293 | The Roman Empire was split into two halves: East and West. |
| 324 | Constantine reunified the Roman Empire under his rule. He moved the capital of his Empire from Rome to the city of Byzantium and renamed it after himself: Constantinople. |
| 476 | The definitive end of the Western Roman Empire. The Eastern Roman Empire continued in the form of the Byzantine Empire, ruled from Constantinople. |
| 518 | Justinian I became the Byzantine Emperor. This was the start of a golden period for the Byzantine Empire. |
| 532 | Justinian I signed a peace treaty with the Sassanids to defend his Eastern border from the Sasanian Empire. |
| 533-548 | Constant period of conquest and war against tribes in Northern Africa under Justinian I. Byzantine territories expanded significantly. |
| 537 | The Hagia Sophia was built in Constantinople - the high point of the Byzantine Empire. |
| 541-549 | The Plague of Justinian - epidemics of plague spread through the Empire, killing over a fifth of Constantinople. |
| 546-561 | Roman-Persian Wars where Justinian fought against the Persians in the East. This ended with an uneasy truce of a fifty-year peace. |
| 565 | German Lombards invaded Italy. By the end of the century, only a third of Italy remained under Byzantine control. |
| 602 | Phocas launched a revolt against Emperor Maurice, and Maurice was killed. Phocas became the Byzantine Emperor, but he was extremely unpopular within the Empire. |
| 602-628 | The Byzantine-Sasanian War broke out over the murder of Maurice (whom the Sassanids liked). |
| 610 | Heraclius sailed from Carthage to Constantinople to depose Phocas. Heraclius became the new Byzantine Emperor. |
| 626 | The Sassanids besieged Constantinople but were unsuccessful. |
| 626-628 | The Byzantine army under Heraclius successfully gained Egypt, the Levant, and Mesopotamia from the Sassanids. |
| 634 | The Rashidun Caliphate started to invade Syria, then held by the Byzantine Empire. |
| 636 | The Rashidun Caliphate won a significant victory over the Byzantine army at the Battle of Yarmouk. Syria became part of the Rashidun Caliphate. |
| 640 | The Rashidun Caliphate conquered Byzantine Mesopotamia and Palestine. |
| 642 | The Rashidun Caliphate won Egypt from the Byzantine Empire. |
| 643 | The Sassanid Empire fell to the Rashidun Caliphate. |
| 644-656 | The Rashidun Caliphate conquered North Africa and Spain from the Byzantine Empire. |
| 674-678 | The Umayyad Caliphate laid siege to Constantinople. They were unsuccessful and retreated. However, the city's population dropped from 500,000 to 70,000 due to food shortages. |
| 680 | The Byzantines suffered a defeat from Bulgar (Slavic) people invading from the North of the Empire. |
| 711 | The Heraclitan dynasty ended after more military action against Slavs. |
| 746 | The Byzantine Empire won an important victory over the Umayyad Caliphate and invaded Northern Syria. This marked the end of Umayyad expansion into the Byzantine Empire. |
Rashidun Caliphate
The first caliphate after the Prophet Muhammad. It was ruled by the four Rashidun 'rightly guided' caliphs.
Umayyad Caliphate
The second Islamic caliphate, which took over after the Rashidun Caliphate ended. It was run by the Umayyad dynasty.
Fall of the Byzantine Empire: Effects
The primary outcome of the decline of the Byzantine Empire was that the balance of power in the region shifted to the Islamic Caliphate. No longer were the Byzantine and the Sassanid Empires the top dogs on the block; the Sassanids had been completely decimated, and the Byzantines were left clinging to what little power and territory they had left compared to the new superpower of the region. It was only because of internal chaos in the Umayyad dynasty in the 740s that Umayyad expansion into Byzantine territory halted, and a remnant of the Byzantine Empire was left unscathed.
This also ushered in a century and a half of stagnation within the Byzantine Empire. It was not until the Macedonian dynasty took over the Byzantine Empire in 867 that the Empire experienced a resurgence.
However, the Byzantine Empire did not fall entirely. Crucially, the Byzantines managed to hold on to Constantinople. The Islamic siege of Constantinople in 674-678 failed, and the Arab forces retreated. This Byzantine victory enabled the Empire to continue in a minor form.
Fig. 4 Mural of the seaward walls of Constantinople c.14th century.
Fall of the Byzantine Empire: Summary
The Byzantine Empire went through a severe decline between 600 and 750 C.E. Many of its territories were conquered by the Islamic Caliphate, including the coast of North Africa, Syria, and Egypt.
The outcome of the fall of the Byzantine Empire was that the balance of power in this region shifted dramatically. In 600, the Byzantines and the Sassanids were the key players in the area. By 750, the Islamic Caliphate held power, the Sasanian Empire was no more, and the Byzantines were left in a period of stagnation for 150 years.
Decline of the Byzantine Empire - Key takeaways
- The Byzantine Empire succeeded the Roman Empire. Whereas the Western Roman Empire ended in 476, the Eastern Roman Empire continued in the form of the Byzantine Empire, run from Constantinople (formerly known as the city of Byzantium). The Empire ended in 1453 when the Ottomans successfully conquered Constantinople.
- Between 600 and 750, the Byzantine Empire went through a steep decline. They lost many of their territories to the Islamic Caliphate.
- The key reason for the decline of the Empire was financial and military exhaustion after a prolonged period of constant warfare, culminating in the Byzantine-Sasanian War of 602-628.
- Furthermore, the Empire suffered severe plagues in the 540s, decimating the population. They subsequently went through a period of chaotic, weak leadership, leaving the Empire vulnerable.
- The impact of the decline of the Byzantine Empire was that the balance of power in the region shifted to the new superpower of the area - the Islamic Caliphate.
References
- Jeffrey R. Ryan, Pandemic Influenza: Emergency Planning and Community, 2008, pp. 7.
- Mark Whittow, 'Ruling the Late Roman and Early Byzantine City: A Continuous History' in Past and Present, 1990, pp. 13-28.
- Figure 4: Mural of the seaward walls of Constantinople, https://commons.wikimedia.org/wiki/File:Constantinople_mural,_Istanbul_Archaeological_Museums.jpg, by en:User:Argos'Dad, https://en.wikipedia.org/wiki/User:Argos%27Dad, licensed by Creative Commons Attribution 3.0 (https://creativecommons.org/licenses/by-sa/3.0/deed.en).
Explanations 
Exams 
Magazine 
