A Persian-Roman Army Fights Muslim Invaders

A 19th century Bedouin warrior The Arab forces facing the Romans would look much like this soldier. (vikingsword.com)

Where is the great historian Procopius when you need him?

We see an amazing lack of information about the final great Roman-Persian War (602 - 628 AD) and the start of the Muslim Arab invasion of the Empire in 629. Because we lack so many details it falls on historians to put their own spin on events. So here I am doing the best an amatuer military historian can do.

The Roman Emperor Heraclius and Persian Shah Khosrau II were is a 26 year long Death Grip of a war that looked like it might never end. But all wars do end. In this case it was with Heraclius at the head of a Roman army marching deep into the Persian Empire and crushing their forces at the Battle of Ninevah.

The Persian War ended in 628 just in time for the first Muslim invasion in 629.

Anarchy in Persia

Shah Khosrau was overthrown and executed by his own son in 627 and peace concluded in 628.

The Persians surrendered the captured lands of Egypt, Syria, Mesopotamia and parts of Anatolia to Rome. The undefeated Persian armies were withdrawn to the homeland.

Over the next four years Persia was in anarchy with ten kings and queens. The final Shah, Yazdegerd III, was thought to be a child of 8 years old upon assuming the throne.

The Persian Empire that faced the invading Arab Muslim armies was bankrupted from the long war, militarily exhausted, had Roman troops still in their country and was in political anarchy.

Shah Khosrau II submitting to Emperor Heraclius

Rome is Supreme

The Roman Empire had decisively won the war and was in the stronger position of the two.

In addition to withdrawing their armies the Persians returned the True Cross to Heraclius. In 630 the Emperor entered Jerusalem by its Golden Gate. Shedding all Imperial insignia Heraclius walked in the city with the cross and restored it to the Patriarch.

The Eastern Empire was at the peak of its fame and power.  But victory masked deep problems.

Like Persia the Empire was financially and militarily exhausted.

Jerusalem had suffered grave damage in the siege of 614. Other cities and farmland over a huge area would also have been damaged or destroyed. Roman Christians held captive in Persia were repatriated and resettled.

With the collapse of the Persian government thousands of Persian Christians migrated to Roman territory under armed escort. This created a new mix of cultures in Roman cities.

Heraclius left Jerusalem and went to the Roman province of Mesopotamia. There he supervised the exit of Persian troops from Roman territory, the return of hostages and the movement of refugees.

A great danger was Heraclius had little time to reestablish governmental rule from Constantinople of the liberated areas. For years provinces like Egypt and Palaestina Prima were ruled from Persia. A Roman Emperor had become but a distant memory. Now the Emperor was back with his tax collectors and attempts to dictate how local Christians were allowed to worship.

Roman-Byzantine reenactor infantryman from the age Justinian.  The Roman infantry facing the Arabs 100 years later might have looked much like this soldier.

The Winds of War

In the year 628 Mohammad dispatched messages to the Shah of Persia, the Roman Emperor, the Governor of Egypt and the Prince of Abyssinia asking them to accept Islam.

In 629 a number of minor raids and expeditions were sent out from Arabia.  Some were defeated and others returned with booty.  In September, 629 a more important expedition was organized resulting the Battle of Mota (Mu'tah).  Some 10,000 Roman troops gave the invading Muslim army a bloody nose forcing them to retreat to Arabia.

Then in 632 Saint Maximos the Confessor wrote a contemporary reference to the barbarian ravages on the frontier that must have been about the Arabs:


When the Muslim invasion began in 633 it was Persia, not Rome, that was the target.

The Romans had beaten back the Muslims at the Battle of Mota. With anarchy in Persia the Muslims no doubt felt it was a softer target.

Eastern Roman Armored Cavalry A possible look for the Roman cavalry. The standard stirrup and saddle were both used by the Byzantine Cataphract, allowing for more powerful lance attacks and making it a bit harder to knock him off his saddle. Reflecting the nature of heavy cavalry, the horse was covered in Lamellar armor that extended down to its knees, giving the horse protection for when charges were made against dense formation. It's head was enveloped in a plate headpiece. From front to back, there was not a place above the knees left uncovered. (necromoprhvsfellowship)

The Roman Army

The historian Warren Treadgold says there were about 109,000 Roman troops in the field in this period.

This number sounds large but is deceptive. The Empire was enormous ranging from the Pillars of Hercules to Italy, the Balkans, Egypt and Mesopotamia. Troops were required everywhere to man fortresses and drive off invaders. The number of troops available to act as actual field armies was a small fraction of the total.

The mix of the available troops is not available to us. How many are infantry? Cavalry? or militia?

We do know that soldiers were in very short supply. Huge numbers of troops were needed to reoccupy the provinces abandoned by the retreating Persian armies. To fill that gap and to counter the Muslims, Heracilus unsuccessfully tried to shift Roman troops from Numidia in North Africa to Egypt which had a minimal garrison.

Another factor in troop shortages, it appears some level of Roman troops were still inside Persia. They were there perhaps because of the internal political anarchy or to "supervise" the peace of a defeated enemy. In any case those troops were not immediately available to face the Muslims on the frontier of Palestine.

Because of the devastation of war tax money was not coming in. So as a "bonus" the Emperor was cutting expenses left and right and the army was not spared. Even Rome's ally the Arab Ghassanid tribe that protected the desert frontiers of Arabia had their funds cut off at the exact time an invasion from Arabia took place.

Rome needed time and peace to rebuild. Neither were available.

The Arab Army

In 632 AD the Muslim army numbered perhaps 13,000 men.

Because of poverty in Arabia and an arid climate, of that 13,000 perhaps 20% was cavalry.  Infantry would have been an untrained tribal mass.

I do not downgrade the power of tribal based warfare. You can ask the few survivors of the Battle of Teutoburg Forest about tribal warriors. An infantry force of 5,000 fanatical Jihadis slamming into your front lines would have frightened the hardest and most experienced of veteran troops.

But to me the true Arab secret weapon was Islamic Blitzkreig.

In warfare terms think Heinz Guderian and Erwin Rommel.  Like the Allied forces from 1939 to 1942 the Roman Army was a traditional slower moving force with lots of equipment, supplies and camp followers.

The German armored units often avoided combat and plunged deep behind enemy lines to attack the enemy in the flank or the rear. Like the Germans the light Arab cavalry units under their brilliant commander Khalid ibn Walid moved like lightening through the harsh, waterless deserts. The Arab cavalry played that same role as the German armor by rapidly covering hundreds of miles from front to front appearing seemingly out of nowhere to attack Roman troops.

Click to enlarge Map details the route of Khalid ibn Walid's conquest of the western portion of the Persian Empire.

The Roman crushing of the Persian Empire made that country an obvious first target for Muslim invaders.

From the Muslim point of view it was also critical to prevent Byzantine military recruiting among the Armenians and the other peoples of the Caucasus region. Troops from the Caucasus had form a major part of Heracilus' army that invaded Persia. The conquest of Persian Mesopotamia was a vital first step before attacking Armenia and thereby deny Heracilus access to new soldiers.

Emperor Flavius Heraclius Augustus The Emperor was at war for about 27 out of  his 30 years on the throne.

Sassanid Persian Armored Cataphract

Map of the Middle East on the eve of the Muslim invasions.

(Bagot Glubb)      (Heraclius)      (Persia)      (Firaz)      (Rashidun)

(Byzantine Army)      (Levant)