How did the Arabs do it?

Before the 7th century the Arabian peninsula was a backwater. There were a few minor ports along the coast but most of the country was a nomadic wasteland. Despite being right next door to two major centers of civilization (Egypt and Mesopotamia) virtually nothing of any consequence happened there for thousands of years. The main currents of history just passed it by.

Then, suddenly, boom! In a few short decades after the birth of Islam the Arabs took on both the Roman and Persian Empires and kicked both their asses! Persia ceased to exist as an independent state entirely and Rome was grievously wounded, losing territories that it had held since the time of Julius Caesar.

How did the Arabs do it?

I mean, obviously Islam provided a unifying vision and a driving zeal, but vision and drive aren’t enough if you don’t have the demographics to back it up. How did a resource-poor backwater with a limited agricultural base successfully take on the might of the existing classical empires? How did they muster enough troops? What made their generalship so much better? And if they were capable of so much, why didn’t they do it sooner?

I would dare say it worked the other way around… for centuries, Rome and Persia didn’t let any local bigwigs in Arabia get too big. Then they both started imploding. I don’t remember exact dates for Persia, but by the time of the Hajira Rome had been declining for at least two centuries! This was used by the Arabian leaders to (finally) break out, ultimately allowing them to contribute (but not start!) the implosion of the then-superpowers.

I thought this question would be about the Mameluks…

In the case of the invasion of Persia, the Persian Empire was still recovering from a really nasty war with the Byzantines, and suffering from enormous civil unrest (in the last four years before the Arabs invaded, there had been ten emperors), as well as rebellion (by the Lakhmids and Ghassanids, although the Ghassanids were more the Byzantine’s problem). So, it was unusually weak at that point.

Plus, the general leading the Arab armies (Khalid ibn al-Walid, the “Sword of God”) was just a great general. The man just couldn’t lose.

Ask Genghis. Never underestimate the power of the right man at the right time in the right place with a winning idea. For Arabia it was Muhammad and Islam.

Reciprocally to what Captain Amazing says, the Byzantines were in pretty poor shape by the end of that war as well. The Avars besieged Constantinople in 626, which gives you an idea of how far the former Eastern Roman Empire had fallen by that point.

So the timing of the rise of Islam couldn’t have been better: the two big regional powers had just pummeled each other to the point of collapse when Muhammed died in 632.

Aside from which, many of the peoples in the area were not particularly loyal to either side and didn not have large (or sometimes any) military. Hence they didn’t exactly give much effort to stop the Arabs.

Didn’t the Mongols do the exact same thing, with even fewer resources and a smaller population?

So, to sum up:

1.) The Persian and Byzantine state were exhausted by over a quarter century of warfare.

In Byzantine Europe much of the Balkans and mainland Greece were essentially sacrificed to the Slavs and Bulgars, as resources were poured into the bleeding east. Italy was being dismantled piecemeal by the Lombards, with no resources to spare for it, either. Egypt and Syria were temporarily overrun by the Persians. And by temporarily, I mean years - over a decade under foreign occupation. The last Persian troops weren’t successfully negotiated out until 630. The Arab penetration began in 633 or 634.

On the flip side Persian Mesopotamia was eventually overrun by the Byzantines, its irrigation systems temporarily ruined. As Captain Amazing noted political chaos descended after the loser in the long war, Khusrau II Parviz was assassinated. The empire descended into near-anarchy. It was the Persian general Sharbaraz that the emperor Heraclius negotiated with in 629 to shift the last garrisons from Egypt and Jerusalem, not any of the ephemeral Shahs busy killing each other over control of their bankrupt and dissolving state.

2.) Religious foment was added to the internal weakening of both the Sassanid and Byzatine empires, as Zoroastrian and ‘Catholic’ ( not to be confused with modern Catholicism ) orthodoxy conflicted with large segments of both states.

3.) The Arabs were highly motivated and at least vis-a-vis outsiders, had a unity of purpose. For example one of Heralius’ greatest strengths had been not any overwhelming military ability, but rather his political acumen at dividing enemies internally. This proved useless against the Muslims who could not be divided against each other. Heraclius’ negotiating skills would be brought in to play only after disaster, when he was forced to sacrifice lands on the eastern border to buy time to shore up his defences in Anatolia.

4.) The Arab client states of the Ghassanids ( Byzantine ) and Lakhmids ( Persian ) had not only collapsed or been dismantled, they generated old enmities that drew Arab forces to advance northwards.

Concordant with that, the Bedouin Arabs that had provided a defensive shield for the desert borders of Syria and its outlying towns and cities were defunded. Not only causing significant resentment at their loss of subsidies, but stripping out Byzantine defences in the area. Civilian populations in this day and era were largely unarmed.

5.) Finaly all the above would have been for naught if the Arabs had not been victorious in battle. The horribly battered Byzantine and Sassanid states were still able to field effective armies and could have won the day. But once these had been lost, they could not recoup their losses to cope.

For example the Byzantine state ( according to Walter Kaegi, at any rate ) had some 98,000 - 130,000 troops on the books at the time of the Arab advance. But only 10,000 - 20,000 were high quality mobile expeditionary forces, the rest were very mixed quality garrison troops and these were spread out defending the empire. At best 50,000 troops were available for the Syrian theater and not much more than half of those ( and the better quality ones ) could be divorced from garrison duty to take the field. Once this force had been essentially destroyed at Yarmuk ( and earlier, smaller Arab victories had already unhinged the region ) , Syrian defences collapsed like a punctured balloon.

Similarly with the Persians - al Qadisyyiah cost them Mesopotamia. Nihavend would cost them the core of Persia and the war.

In all of the above battles the Arab forces were outnumbered and except perhaps in terms of somewhat superior mobility ( and whatever morale advantages at least some zealotry confers ) had no great edge over the experienced soldiers they were facing. But they won and by winning they broke the backs of the exhausted states they faced.

Once Syria, the manufactuary of the Byzantines - and Mesopotamia, the economic engine and site of the capital of Persia - were lost, the situation became that more dire. The Arabs now commanded interior lines and ( however ruined ) vastly greater economic resources that were denied the old empires. Large, disgruntled Arab populations in Syria, the former protectors of the region, joined the victorious new movement, swelling Muslim ranks. From there on it just became a snow-balling affair.

  • Tamerlane

The same thing that people look at as a weakness of the Arabs today, was at that time their strength. For some reason Islam provided them with such a Zeal that they were able to pull of magnificent feats when outmanned and outgunned. They just kept going no matter what.

Correct me if I’m wrong but my understanding was that central Asia, although thinly populated, is huge enough that it’s total population of nomadic herders was stupendous. What Genghis Khan did was simply put them all under one leadership; and with the mobility to move thousands of miles, the Tartars, Mongols and other steppe dwelling peoples were able to swarm out of Asia like locusts out of the desert.

You know, throw in a couple of bad jokes, and that looks like a better than average Staff Report.

I knew I wasn’t paying the $14.95/year just so I could respond to surveys about my self-love habits. Thank you (and the other heavy hitters who tackled this question) for the reminder.

Genghis Khan’s strength was in his ability to coordinate and communicate quickly moving forces. His powerful cavalry could move across Asia and communicate effectively through a system of messengers, and then they’d sweep down and surprise attack the enemy.

I don’t have time to expound on my readings about GK, but I think John Keegan had some interesting insights in his History of Warfare. The super shorthand version is :

  1. not being tied to the concept of face-to-face decisive battle, GK could better use his mobility, converting from harassment to deadly serious effort and back as the fluid situation required

  2. techniques of herd management learned from herding lifestyle…I kid you not. (E.g., panicking a crowd, enveloping formations, picking off natural leaders, utter ruthlessness in slaughtering, etc.)

edit: not to dispute your point that his communications and scouting were far superior!


Sailboat That’s interesting about the herding thing. I never thought of that.

Another thing about the seventh-century Arab expansionists is that they were great co-opters of existing infrastructure. The Sassanian (Persian) empire and other rulers in the region had huge chunks of administrative bureaucracy, lines of communications and trade, etc., already in place.

Rather than purge the governing structure of a conquered state and attempt to rebuild it from the ground up, the Arab conquerors (like Alexander before them) generally just took over the bureaucracy and kept it running largely as before. Modern imperialists take note.

Tamarlane, thanks for an excellent summary.

And thanks to everyone else as well!

Hmmm … maybe this wasn’t a debate after all … .