Why did the Western Roman Empire collapse but not the Eastern Roman Empire?

Question

There were several crises in the “late” Roman Empire.

For once, the crisis of the Republic, which resulted in the creation of Principat and later Dominat. This crisis may be related to the fact that due to an end of territorial expansion, the constant stream of slaves ran dry. By then, slavery had by large replaced traditional farmers, who had been the backbone of the Roman army. This crisis resulted in a population drop from about 50 million to about 30 million. (source: Kautsky)

Then, there was the crisis of the third century which almost caused the collapse of the Roman Empire. Ursupator states were formed in the West and the East. This crisis was eventually overcome, and both the Gallic Empire and the Empire of Palmyra were re-integrated in the Roman Empire, but in the Western half, this success did not last for long. By 500, the Western Empire had vanished, while the Eastern Empire remained intact for almost 1000 years.

Now there are several factors in which the Western and the Eastern Empires were different. I believe that in the Eastern empire, slavery never played a role as important as in the Western empire, i.e. there were no huge latifundia with hundreds of slaves, so the end of slavery did not mean that much of a catastrophy in the Eastern half.

Furthermore, the Eastern empire is often said to have been technologically further advanced, had more population and was richer, but I am not sure if or why this would be true.

What are your thoughts?

Edit I cannot help but wonder why most answers claim military circumstances as reason for the decline of the Western Empire. The Roman Empire constantly faught wars with its neighbours, which before never caused to major crises, and the most fericious enemy, i.e. the Persians, were faced by the Eastern Empire, which did not collapse around 500. This wikipedia site lists several theories about the decline of the (Western?) Roman Empire, the vast majority of which do not boil down to military circumstances.

Answer 1

The following is according to Karl Kautsky. In order to understand why the Eastern Roman Empire did not experience a crisis as deep as the Western Empire in the first centuries, it is important to elaborate on the nature of the crisis that occured.

Bare that understanding, one can only cite differences based on random-individual characteristics (superior diplomacy, wise military leadership) or random-geographical circumstances (bordering nations, the Hellespont). Those are not satisfactory, as there are numerous such circumstances, each of which could be easily interpreted to favour or disfavour the collapse of the Western/Eastern Roman Empire.

So, what exactly is the nature of the crisis that affected the Roman Empire starting around the time of Christ’s birth? Let us start with the proposition that all societies based on slavery have a tendency towards crisis and eventual collapse. Why is that so?

• The vast majority of the economy in the ancient world was based on subsistence economy. Farmers produced everything they needed, and only a minority of the economy produced luxury goods or tools.
• Slavery was much less efficient than small free farms, but it allowed the landlord to reap a larger total profit. Starting from the punic wars, latifundia, although being less efficient, started to replace small free farmers, who could not compete against the latifundia. Farmers who lost their land went to the cities, where they found no jobs and were dependant on bread and games provided by the rulers.
• Without other possibilities to invest (there is no point in inproving technology in slave-based agriculture), landlords spent their profits on luxury consumption (and bread and games).
• Slavery is dependant on constant expansion and warfare as source for new slaves. Under the harsh conditions of slavery in the mines and at the latifundia, slaves do not live long lives and having slaves raise children is not profitable.
• At the times of Roman expansion, the backbone of the army were free farmers. Farmers are used to withstanding harsh weather conditions. Slaves do not make good soldiers, neither do poor urban masses. With the widespread of slavery, Rome had to recruit Germanic mercenaries to man the legions. Maintaining the army meant that the state had to introduce high taxes. However, without the benefit from acquiring slaves, landlords had no motivation to support a state apparatus that brought no benefit to them.
• The victory of slavery as the main mode of production caused a rapid population decline, as in total, slave-based agriculture is much less productive than free farmers are. Without slaves, around 100–200 AD, Roman agriculture collapsed and vast areas ran to seed. What followed was the era of the colonate, which meant that formally free farmers, probably former poor urban proletarians or soldiers, were assigned land and had to pay massive taxes to support the state.
• Population and manpower decline, disinterest of the ruling classes and the masses in maintaining the army and overall low productivity meant that neighbouring tribes saw unused but fertile Romand lands and the luxury of the landlords as a cheap opportunity to seize. Bear in mind that the Germanic tribes had a more productive economy and an intact social base of the army, both of which the Roman Empire did not have at that time due to the reasons cited above.

So far, this explains why the Germanic tribes succeeded in overthrowing the Roman rule, while the Gauls did not, but it does not explain why the fate of the Western and the Eastern Emire differed. The main reason for that is because the Eastern Empire was hit by the crisis to a far less extent than the Western Empire.

• As explained above, slavery was less productive than free agriculture, but it gave birth to luxury consumption on a larger scale. However, all products consumed in luxury were produced or traded through the Eastern Empire. While the Western Empire was agriculture only, the Eastern Empire engaged in trade with China and India, was the center of science, produced the art that was popular in the Roman Empire and also manufactured goods such as linen, papyrus, pottery, etc. All the surplus extracted from Western Roman slaves was used to purchase goods fabricated in (or traded through) the Eastern Roman Empire, which thus differed from the Western Empire in having an economic base besides agriculture. This allowed the Eastern Roman Empire to field a stronger army than the Western Roman Empire.

• So why did the Eastern Roman Empire have more industry? Because, in the West, all the Romans did after conquest was to pillage and set up large slave-based latifundia. In the East, the Romans profited from the collapse of early high cultures such as egypt and the other former Alexandrine states. Those societies were not primarily slave based (e.g. Ancient Egpt) and thus managed to develop efficient economies that produced enough agricultural surplus that was in turn used to develop other branches of the economy in thousand year long processes.

• This does not mean that there was no economic collapse in the East. But the crisis was not so severe that it led to a complete dissolution of the state apparatus as in the Western Empire except Italy and its replacement with Germanic kingdoms around 400 AD.

• The stress resulting from very same transformation of a slave-based economy to a more feudal system, that happened in the West and the East at the same time, could be mastered by the Eastern Roman Empire not due to the brilliancy of its leaders but the superiority of its economical base.

Answer 2

Furthermore, the Eastern empire is often said to have been technologically further advanced, had more population and was richer, but I am not sure if or why this would be true.

That was indeed the case. Eastern Mediterranean ("Levant") in general had civilization superior to the western part of the Roman Empire (btw there was only one Roman Empire - what we call Western Roman Empire is the part of the Empire governed by the Emperor of the West). That started to turn around only around 1000 AD.

In my opinion, the key event for the fall of the West was Vandalic invasion of North Africa in 420s AD which took away critical economic resources from Romans. They were aware of that fact and there were several attempts to recapture Africa. All failed until the expedition of Belisarius in 530s AD.

Answer 3

Lars Brownworth discusses the survival of the Eastern Empire and by tangent the fall of the West in "Twelve Byzantine Rulers" in Episode 5: Zeno. His book by the same name presumably discusses the same. The podcast discusses the general situation at the time of the various emperors essentially being puppets of barbarian generals and the like. The fall of the West wasn't some immediate thing.

The last emperor was deposed but it wasn't until later when no new Emperor was crowned that the empire "fell". It was more that was the end of direct Roman control over the remains of the Western Empire. The Eastern Empire avoided this fate by the work of Zeno who managed to through off the barbarian yoke in the east and forged a solid state that proved durable enough to survive as a united thing.

Odoacer and later Theodoric both payed homage to the Emperors in the east but after Theodoric died, the later kings and chiefs in Italy didn't mint imperial coins or do otherwise to show any kind of fealty to Constantinople. This eventually prompted Justinian to invade Italy.

Answer 4

The biggest difference between the military threats of the Goths and the Huns compared to Persia was the migratory nature of the former versus the centralised (and thus spatially constrained) government of the latter.

Rome and Persia had sparred against each other in the mesopotamian region for centuries, but, though one or the other might gain ascendancy, they were unable to maintain their advantage beyond their centre of gravity.

In contrast, although germanic tribes had been fought off by the legions repeatedly over the centuries, when the Goths did finally break into the Empire, they brought their entire nation with them. It took just one sustained failure to deal a fatal blow to the Empire.

Note that one of the reasons for the continued ebb-and-flow of the balance of power between the Persians and the Romans was that the Persians were also having to hold off similar migratory opponents on their north-east border (not always successful, as illustrated by the Parthian rule between the two Persian empires).

In this sense, Persia acted as a buffer for the Eastern Roman Empire, leaving only a small part vulnerable, north of the Black Sea. A good reason for the quality of the defenses of Constantinople!

Answer 5

The Eastern empire kept more of its troops on the borders, while the Western empire kept more troops close to the Emperor. The East also developed diplomacy to a fine art, which was a bit lost on their Western counterparts, and so was able to survive without being the toughest nation out there by a good margin.

Answer 6

In the "early" going, at least (fourth and fifth century A.D.), part of the differences in the fate of the Roman Empires had to do with the movements of the Goths and Huns. http://en.wikipedia.org/wiki/Goths

"To make a long story short," the Huns chased the Goths out of Eastern Europe and the Balkans (e.g. HUNgary), and these people in turn migrated to, and took over the Italian peninsula and western Europe from the Western Romans. No such thing happened to the Eastern Romans (in modern day "Asia Minor,") and they were spared for almost a thousand years.