The Persian Wars of Heraclius

Last Updated on November 27, 2023 by Vladimir Vulic

by Kurs

In this article, I will try to throw some light on the Persian campaigns of the emperor Heraclius (who reigned AD 610 – 641), which in most historical books are much left in the dark. My main inspiration was the marvelous book „Die griechischen Kaiser“ (The greek Emperors) by Frank Thiess. It is deplorable that as far as I know it hasn‘t been translated into English, for its vast detail and vivid style makes it very recommendable, apart from the fact that he is too uncritical of the sources, and his literal style is sometimes ornamented with personal interpretations which nevertheless give the story a human touch (sometimes it seems indeed more like a novel), although he passes on many errors which have been corrected today (it’s an older book). He covers the period of the successors of Justinian till the end of the heraclian Dynasty.

For an overview (in a structural sense) of the seventh century there is John Haldon’s „Byzantium in the seventh century“. Very detailed is the first volume of A.N. Stratos‘ „Byzantium in the seventh century“ (602-634).

Useful was also the general „Byzantine history“ of Georg Ostrogorsky, also John J. Norwich’s „Byzantium – the early centuries“. For army material I refer to Warren Treadgold’s „Byzantium and its Army“. Detailed and up-to-date information is produced by J.D. Howard-Johnson in his Article „The Siege of Constantinople“, published in „Constantinople and its hinterland“, edited by Cyril Mango and Gilbert Dagron. See also Howard-Johnston’s articles „The official history of Heraclius‘ Persian campaigns“ (in „The Roman Army in the East“, edited by Edward Dabrowa) and „Heraclius‘ Persian campaigns and the survival of the East Roman Empire 622-30“ (in: War in History (Journal), 6, 1999). An English translation of the Chronicle of Theophanes has been edited by Roger Scott and Cyrill Mango. Before starting, I would like you to make some allowances for the fact that English is not my native language. So if there are some confusing phrases, „boring“ repetitions of words or wrong terms, I apologize. But I hope that it will always be clear what I mean. If you have questions, feel free to e-mail me ([email protected]) and I will try to answer them as best as I could.

I. Introduction: The Story so far

The Reign of Phocas

Under the reign of Maurice, the fortunes of the Empire had been revived: After a long, exhausting war the Persians were finally defeated; not going into detail it is to be noted that the Persian King Chosroe II after an outbreak of civil war owed his throne to the help of Roman arms and became the loyal friend of Maurice. On the Balkan front, the situation had been much improved by successive campaigns; it even seemed possible to restore the old frontier on the Danube. But the overthrow and murder of Maurice changed everything: Under Phocas, formerly a non-commisioned officier in the Balkan army, the empire collapsed.

From the very beginning of his reign, Phocas was faced with insurgency and revolution, to which he had no answer but terror in an extent perhaps unequalled in Roman history. But this accomplished nothing. The misfortunes were further enhanced by the hate of the circus factions, the green and the blue, each at the other’s throat and making good use of the widening anarchy, also by riots in the east by the Jews and Christians alike in an attempt by one to destroy the other. Troops sent to restore order were dispersed; the only parts where order was maintained seemed to be the Exarchats of Italy and Cartharge, and, with growing difficulty, the Capital. In the East, parts of the Roman Army under Narses, the commander in Mesopotamia, revolted against the ursurper, calling the Persians to help. Chosroe was only too glad for the opportunity: On the ground of avenging his former saviour Maurice (and putting forward a puppet ruler he introduced as the legitime heir of the late Emperor), he now waged war against the Empire (AD 603). But that was only a pretext. Phocas had to move parts of the Balkan Army to the east to meet this threat. So the Avars and Slavs at length succeeded in virtually bringing under their control much of the peninsula and penetrated as far as Greece.

On the eastern front, the ill-prepared troops of Phocas managed to hold their own for some time. They besieged Edessa, where Narses had assembled his troops, in 604, and won a small victory in Armenia. But the troops at Edessa were beaten by Chosroe, who advanced from Dara, to which he had laid siege. Narses was burnt alive in Constantinople after he had gone there to negotiate (he had been promised safety). Edessa was then for some time held by the Phocas troops, but finally fell into Persian hands (in AD 609). In 606 they captured Dara after a long siege. The garrison was massacred, the population deported. The troops of Phocas were by this time commanded by his nephew Domenziolos, who could do no more than regroup and wait. After he too was beaten in 607, there was no longer any serious resistance. Gradually the Persians conquered Mesopotamia and Armenia. Parts of Asia Minor were raided by Persian soldiers, Caesarea captured. In AD 609, the Persian General Sahin reached the Marmara; but it was only an advance guard of Chosroe’s Army. Constantinople was not yet seriously threatened.

By this time, Phocas was openely cursed by the whole population. Revolts and conspiracies ranged all over the empire, notwithstanding his brutal reactions. In Constantinople many senators and other leaders were killed, often by burning them alive, which was a favorite sentence of Phocas. By this inhuman conduct he did more damage to the Empire than the external enemies. In AD 608, a revolt broke out in Antioch. Phocas send a great part of his remaining troops under the scribo (an officer of the excubitors) Bonosos to put it down. Despite the Persian danger, he collected the remaining troops in the East and quelled the revolt. 10,000 men are said to have been put to death. However, the threat to the imperial throne now shifted: In Cartharge, the Exarch Heraclius (the elder) had long been quiet, pretending to be loyal but determind to stop Phocas before he let the Empire be cut to pieces. He was in secret communication with Sergius, the later Patriarch, and the General Priscos, Count of the Excubitors (who had distinguished himself during Maurice’s reign), now son-in-law of the Emperor but carefully helping his former comrad-in-arms Heraclius with precious information. So the latter knew about the situation prevailing in Constantinople and the ever growing opposition against Phocas. He now decided it was time to act. To secure his position, he put an army under the able command of his nephew Nicetas to capture Egypt. When news of this reached the capital, again Bonosos was sent to defend this precious province. Nicetas captured Alexandria very soon, but when his generals marched on, they were defeated, and for some time the issue was in the balance; but with the help of the population, Bonosos was finally defeated and had to return to Constantinople (Spring 610).

Now was the time to overthrow the ursurper; and in May 610 Heraclius (the younger), son of the Exarch, sailed off first to Thessaloniki and then on to the capital, were he was hailed as a deliverer. There seemed to be no serious resistance; Phocas had not made any preparations (and could not: his fleet had been mostly lost in Egypt, the demes revolted when Heraclius came in sight and the Excubitors –although assembled by Priscos- did apparently nothing to defend Phocas); only Bonosos (who was killed later) made a feeble attempt by armouring some of the grain ships, which were sent to the ground at a moments notice by the warships of Heraclius. The truth was, any support Phocas may once have held by now had gone with the wind; and so he was brought before the victor, who asked: „Is it that you have governed the Empire?“ And Phocas replied, defiant but with at last a bit of spirit: „Will you do it any better?“. He was than handed over to his enemies in the capital and tortured to death by those he had terrified so long.

On the same day, October 5th, 610, Heraclius was crowned emperor in the Church of St.Stephanos by the Patriarch Sergios and sent back notice to his father, who had remained in Cartharge. Soon afterwards the Exarch died, remembered by history as the founder of the first Byzantine dynasty.

Struggle for Survival

What Heraclius had inherited from Phocas, didn’t very much resembled the empire of Maurice. It was a devasted field of burnt cities and deserted lands, of hunger and starvation. Morale had collapsed. In Syria Persian arms advanced. Egypt was devasteted. The Balkans were mostly lost from effective imperial control. Italy had its own troubles. There was not much left of the Roman field army, its remnants were demoralized and scattered. There were no soldiers, no provisions, no arms and above all, no money. What was left was used to buy an unstable peace from the Avars and Slavs (which had to be renewed in 620 and again in 623 after breeches of the truce by the Chagan and new disastrous incursions. – The financial situation was eased a bit when Heraclius cut military pay in half in 615 and the Church handed over, at the proposal of Sergios, large parts of its wealth). Constantinople itself was restless and shaken by an earthquake in 611. Heraclius even seriously considered to move back to Cartharge to direct affairs from a calmer shore, but was persuaded by Sergios and the desperate people to stay. This helped a bit to restore some hope. But most was done by the Patriarch, who worked day and night to envoke a new spirit in the population.

In 611 the famous Persian general Sahrbaraz captured Antioch and Emesa. It seems that Nicetas tried to stem the avance but was beaten. Nevertheless, the Persians then halted for nearly two years.

Heraclius first had to solve his army problem. The solution he had in mind needed time; so at least he had to stop the foe from further penetrating Asia Minor. For this he sent what was left of his army into Cappadocia. They succeeded in recapturing Caeserea (612) and marched on into Armenia. But here they achieved nothing more, and soon were compelled by an army unter Sahin to withdraw. Another expedition was led by Heraclius himself via Tarsus against Antioch in 613, but was defeated and had to retrace its steps, losing parts of Cilicia to the enemy. But even when the results were unfavourable, these first campaigns showed to Heraclius that the Persians did not contemplate yet to march further into Asia Minor and in the direction of Constantinople: Chosroe seemed to think that the empire would fall apart anyway, and thought it not prudent to try to conquer the Empire’s heartland. So he allowed his troops to be dispersed and „absorbed“ by the mere space of the Empire‘s provinces. It was, I think, to prove his greatest mistake, though from his point of view it was of course a sound plan first to conquer the provinces and so weaken and „surround“ the capital of the Roman Empire (we must bear in mind that large European parts of it very also mostly lost to the Avars) before the final punch. When Armenia and Mesopotamia were in Persian hands, they raided Asia Minor. When it in turn was devastated they turned to Syria and Palaestine, and on to Egypt and Africa. But these acts, although being heavy blows of course, had no decisive strategic value in the end, and gave Heraclius the sorely needed time. He had to sacrifice these provinces (having not the means to recapture them anyway), but as he had long realized that this was a war for survival and could only end either with ultimate defeat (which meant the fall of the empire) or ultimate victory. And he was prepared to commit this sacrifice. When the war was to be lost, it would make no difference; was it won, the lands lost would be recovered at a stroke.

From Emesa the Persian army of Sahrbaraz marched on and took Damascus, and then it was Jerusalem’s turn:, After brief but sharp resistance the Holy City fell on May 22, 614. There followed a massacre of the Christian inhabitants. More than 57,000 people are said to have been slaughtered. But perhaps worse in contemporary eyes was the capture of the Holy Cross, which was carried off to be kept by Chosroe. The Christian Empire seemed indeed doomed. Two or three years later Sahrbaraz, after some preparations, marched on Egypt, took Alexandria (Nicetas fled before the city was handed over by General Isaac – Nicetas later became Exarch of Africa, where he ended his life), and went on to Lybia and even Cyrene and Tripolis (according to Theophanes, although it seems he did not actually reach them). But perhaps this was in a way good news for Heraclius, for he knew the dreaded Sahrbaraz at safe distance. In Asia Minor, Sahin in 615 again appeared at Chalcedon. This time the emperor sent him a reproaching note (or even confered with him in person) and menaced him with God’s revenge for the waging of an unjust war, and advised him to return to his king, to whom he would send an embassy and a proposal of peace. This had its impact: Sahin retreated, to the anger of Chosroe, who had the members of the embassy, who accompanyied Sahin’s army, thrown into prison, where they died.

After this threat was over, Heraclius set to work in earnest for the reorganisation of his army.

The Themes

It is not the purpose of this article to describe fully the new provincial system which Heraclius began (and which would take some time after him to be completed), so I will pay this only short notice. The Themes, first created in Asia Minor (which was in danger but still mostly free of the enemy), were like the exarchat units of administration with a military view. At its head stood the Strategos, combining the highest military and civil authoritiy (although at the beginning the civil administration remained supreme). The „Thema“ actually described an army-corps, so in each Theme the soldiers were not only stationed, but received land to settle, which would pass along the generations by heredity. In turn, they were to serve when summoned, and received but little pay, beeing able to sustain themselves. So the new system not only laid the roots for a new people’s army (the empire no longer needed to turn to foreign mercenaries), but also diminished the costs for its maintainance considerable.

Treadgold has traced down where the old armies of the Justinian system, or what was left of them, were later found in the new system. In general, the troops of the praesental armies seemed to be settled in the big Opsician theme in the relatively secure north-west of Asia Minor. What was left of the army of the East now moved to Anatolia, while the Armenian troops stayed in most western parts of Armenia as it was mainly under Persian control, I think it possible that we may find them by this time in the regions of Cappadocia. The survivors of the army of Illyricum, which seemed to have nearly perished, in time settled down the Carabesian theme in the south (and the aegean islands), which later became the maritime theme as we know it. The army of Thrace, which had fared better in comparison, received land on the western coast in the Thracesian theme. As mentioned, the theme organisation at the beginning was restricted to Asia Minor, which was the last stronghold of the empire rich in resources. It will be noted that this arrangement meant for the time being the loss of most of the Balkan peninsular. But its defence had long been defective, and Heraclius considered the Avars and Slavs the lesser danger, knowing that neither of them could capture the capital, nor were they able to cross over to the Asiatic shore.

Treadgold, Haldon and other historians in modern publications throw some doubts on the question wether Heraclius was really the creator of the theme system and tend to attribut it to his successor Constans II. But I think that Heraclius at least began it. I don’t think it probable that he did nothing in the years between 613 and 622. I think he noticed by his first campaigns that the army in its present condition could not carry on the war, and that he then sat down to reorganize it and reduce its costs. I cannot imagine that he left the army idle in the field for nearly ten years if there wasn’t really a need for changes. I would conclude from what I read so far that he began a system in which the troops were billeted and settled over wide spaces of the empire, out of the necessity to maintain them and to give them some compensation for cutting their pay. So I would still think that the origins for the themes were laid during his reign. Probably it was not as toroughly organised as sometimes thought and perhaps not meant as a permanent institution. It was a system invented out of necessity and the prevailing situation of external danger; and when later this danger became permanent during the rise of Islam, it was completed and made permanent by Heraclius’ successors.

II. The Dragon shows his teeth

The First Campaign (AD 622)

In the spring of 622 the emperor began assembling the available troops at Nicomedia. He bade farewell to the capital, now to be commanded by the Patrician and Magister (militum?) Bonos and protected by the prayers of Sergios. He moved to Caesarea (Howard-Johnston thinks it more likely that he stayed in Bithynia), and in the following weeks he trained and disciplined his force, bringing them up to the shape of fighting units and envoking in them the necessary confidence. The army was called Philochristos, the „Elect of Christ“.

Its strength is given at 120,000 men. That figure is definitly too high and deserves consideration. The army still mainly consisted of the remnants of the former Praesental armies of Illyricum, Thrace, Armenia and the East, even when they were now settled in new areas and had a new organisation. It is acknowledged by most historians that the overall strength of the field army at the end of Justinian’s reign was about 150,000 (as given by Agathias). Treadgold with good reason reckoned that by the end of Maurice’s reign the number could not have been higher, and was perhaps lower. So let’s assume that before the various disasters of Phocas’ reign the total field army was still close to 150,000 men strong. From this we have to neglect the forces of Italy, Africa, and Spain which were needed in their own realms and took no part in the campaign. This leaves about 110,000 men. Treadgold by a rough estimate reckons the total field army’s strengh (including Italy and Africa) in 641 at 109,000 men. Reducing the forces of Africa and Italy, this seems to be about in line with 773, when the troops settled in the themes of Asia Minor were about 78,000 men, so that its sure that there must have been severe reductions. It‘s certainly harzardous to speculate on figures given a hundred and fifty years later, but I think we can at least assume that after the heavy blows during the first ten years of the seventh century the remaining strength could not be higher than this. The army of Illyricum had suffered very high losses in the wars with the Slavs and Avars. The somewhat stronger army of Thrace suffered not as much in proportion, but also severely. The army of the East, which partly had revolted against Phocas soon found itself between the Roman and Persian adversaries, and not much of it could be left. The Armenian troops had fared better, but as Armenia was overrun, I think it probable that they too were much reduced. As it seems likely that parts of the praesental armies were used to put down the revolts in Syria and in the attempt to hold Egypt against Nicetas, the rest being involved against the Persians, they in turn must have sustained losses, perhaps on a lesser but still substantial scale. It is impossible to show the extent of these losses, but as a personal estimate I would presume that the whole force Heraclius could draw on (again exclusive Africa and Italy, Spain being mostly lost in 616) did not exceed 70,000 men, even if we make allowances for the fact that every available soldier was assembled; including some garrison troops, formerly not belonging to the field armies. And there must have been reductions for the protection of the capital and at least small forces left in Asia Minor to guard the communication lines. So perhaps a number of about 50,000 who actually were available is reasonable. But this is only my personal estimate.

I am of course aware of the fact that armies by this time were usually not stronger than 30,000 men. But I don’t want to rule out the possibility that this one was larger. It would be unusual, for the campaign was in effect an all-or-nothing effort. But on the other hand, given the speed with which the army later moved, it appears again probable that it was not that large. Unfortunatly, there is no reliable source, and I don’t know of a definite statement of the numbers involved.

Back to the story, when enough training (and studying – Pisides writes that Heraclius „gave battle before the battle“ by reading all available military sources and planning marches and battles) was done, Heraclius assumed the offensive. The Persians had left Asia Minor alone for some time, although there is a reference that in 620 they had raided Ancyra (it seemes more probable, though, that this took place in 623 or 624). Chosroe entrusted the command of his army to Sahrbaraz, who spend some time in concentrating his troops. Heraclius marched on to the Pontus region. He now stood between Sebasteia and the Euphrat, Sahrbaraz was guarding the passes to the east (Winter 622). Heraclius by a flanking manoever succeeded to turn him; he now occupied the former’s position. Sahrbaraz did not dare at first to attack him. He was inclined to move into Cappadocia and so drawing the Romans with him. But because Heraclius soon moved further east (probably on the Satala-Theosiopolis-road), he had no other choice but to follow. In February 623, after several failed attempts to come to grips with the Romans and intense skirmishing, Sahrbaraz decided to attack. He divided his army into three groups to charge the imperial forces in front, while one part was hidden in a small valley to await the opportunity to ambush the Roman forces. But the emperor was kept well informed by his scouts, and attacked with picked men the ambush force and completely defeated it. Sahrbaraz had no other choice but to withdraw, leaving Pontus and the way into Persian Armenia in imperial hands.

Although the victory was important especially from the psychological point of view, the situation was still precarious. The emperor intended to resume the offensive by marching into Lascia; but before that he had to return to Constantinople to avert a new threat by the Avars, who had entered Thrace. He was enthusiastically welcomed (March 623); but he was sure that this first success was only the beginning, and that Sahrbaraz was not likely to be discouraged by his reverse, and would be back soon. So he made one last effort to conclude a truce with Persia, but Chosroe would not listen to the possibility. There was no alternative but to battle till the end, but Heraclius knew that now the whole population and army stood firmly behind him, trusting in god and praying for victory.

The second Campaign (AD 624/625)

Heraclius spend the rest of the year in Constantinople, and succeeded, after some difficulties, to arrange a new peace treaty with the Chagan. The Persians left the Roman army undisturbed the whole year and did nothing to prevent a further advance into Armenia. But they surely needed some time to regroup their defeated forces, and an attack was made on Rhodes during this time.

The army had encamped in Pontus. Heraclius returned to it after celebrating Easter in the capital. Sahrbaraz meanwhile was no longer idle. On the king’s orders he marched west again in the hope that Heraclius would follow and attack him. It is possible that the mentioned occupation of Ancyra took place due to this manoever. But Heraclius paid no attention to this new threat to Asia Minor. He knew that Sahrbaraz alone could not accomplish much, and he was determind to further advance into Persian Armenia, knowing that the enemy was very weak in this region, for Chosroe had committed the blunder, out of a incredible feeling of security, to send home the forces of Sahin. As the emperor led his forces forward, he reckoned that Sahrbaraz would probably be recalled.

The army crossed the Euphrated and took Theosiopolis, which opened the gates to the emperor. On they marched, along the north bank of the Araxes river to the capital of Persian Armenia, Dovin, which offered resistance but was also taken (May 624), and to Naxcavan in the south-east.

The next steps lead the army south, crossing the Araxes into Aserbeidjan (Atropatene). It was summer now, but despite the heat the army moved rapidly. Passing between Taebris (Tauris) and the Urmia-Lake, they conquered the city of Ganzac which was captured after Heraclius routed the troops sent (and perhaps commanded in person) by Chosroe from Ctesiphon to intercept him in July 624. The Roman army stood deep in Persian territory at the back doors of Ctesiphon, which itself, less than 300 miles away, was in danger. They had moved with incredible speed, covering a 1,000 miles in about nine weeks.

Now Chosroe had to pay for his strategic errors (he himself had some difficulties to evade the Roman troops and return to safety). Sahrbaraz had been hastily recalled, but did not reach the scene to intervene. Another army was raised (the Persian strength is given for 40,000, which is probably too high). Heraclius took his revenge for the capture of the Holy Cross and destroyed one of the oldest and greatest temples of the Zoroastrian religion at Ganzac. After that he resumed his march south, but then turned northward again. Persia was not yet weak enough to be overcome. Had he tried to capture the King’s residence, he would perhaps have succeeded, but Chosroe could flee to the East, and Sahrbaraz and the new army under Sahin would be at the Roman’s front and rear. Heraclius understood that, and after convincing his soldiers (who were eager to finish off their foes) he was able, under increasing annoyances by the hands of Sahin, to reach winter quarters in Albania at the Caspian Sea. There he had to spend some time to subdue the local chiefs and collect provisions. But his army suffered all hardships without trouble. Much had changed since the days of poor Maurice! (Who was overtrown by the Balkan troops, enraged by his orders to winter in enemy territory.) Heraclius was then compelled to move further north-west, till in January he took his second winter quarter in the south-east of Tiflis, well between the Black Sea and the Caspian. There he obtained help from the Abasgians and the Lazi. Sahin (whose force according to Sebeos was 30,000) was now waiting for Sahrbaraz, who had arrived at Niniveh, and a third army under the General Sahrblaganaz. Before they could unite, in Spring 625 Heraclius, again lead his army south, accompanyied by his new allies. But Sahrblaganaz prevented him from continuing in the direction of Atropatene, and he turned west towards Siouania. It was now summer, and Sahrblaganaz and Sahrbaraz combined their forces and advanced against Heraclius, not waiting for Sahin, who was not yet up. The ensuing battle was fought in the vincinity of Tigranokerta. I have not been able to locate this town definitly. It certainly has nothing to do with the old Parthian capital in Mesopotamia, as Thiess still believes. An e-mail reached me stating that it was in the Kura-Valley. Concluding from that and the fact that Heraclius tried to gain his way into Siouania, I would place it somewhere east of Lake Shevan. Sahrbaraz closed in from north of the lake, whereas Sahrblaganaz came from the south (and Sahin was in the west?). This would show how fairly the Persians succeeded in shuting up the Romans in Albania.

Back to the battle: First, by the means of a faked retreat, the emperor ambushed the forces of Sahrblaganaz (who was wounded or killed) and Sahrbaraz, defeating the famous Persian leader for the second time. Then he pushed back the advance guard of Sahin, who arrived at a bad time and had to withdraw to the town. The attack was continued, and Sahin was compelled to leave his camp und fled, combining only then his forces with Sahrbaraz, who had also collected the remnants of the army of Sahrblaganaz. It was a significant victory; three armies converging on the Roman soldiers had been defeated, although the Persians were soon able to resume operations. Heraclius again made an attemt to penetrate into Atropatene, this time by moving to the western side of the Lake Urmia. But he would not succeed and decided to withdraw again, for his allies had left him at this point. He was constantly harassed by the Persians. When he was marching back, he got wind of a Persian force of about 6,000 picked men at Acres, at the north-east of the Lake Wan, Sahrbaraz being with them. Heraclius on a cold winter night attacked, and they soon fled to the south, including their leader (said to have escaped only naked). Now at last the Roman troops could get some rest and took up their richely deserved winter-quarters.

The third Campaign and the Siege of Constantinople

The Persians now made their major attempt to destroy Heraclius. Beginning the campaign in March 626, Sahrbaraz and Sahin succeeded in driving the Emperor west (and so diverted him from continuing his counter-offensive). A huge force of Avars and Slavs, with which Chosroe stood in communication, was to invade Thrace and threaten the capital itself. Chosroe hoped that Heraclius would rush back to its protection, losing his jump-off positions in Armenia. The Persians would then be able to direct the war again in Asia Minor, and by this time perhaps could crush the Roman Army between them.

It was a sound plan, but Heraclius did, as usual, the unexpected. Reaching the Cilician gates (in April, via Amida, Samosata, Germaniceia), after several engagements (in one he himself was wounded), Heraclius changed direction, not wanting to be pressed towards Constantinople, and moved north to Caesarea and then to Sebasteia. From there he could intercept the army of Sahin, who was advancing through Armenia, and stayed well in the back of the army of Sahrbaraz, who nevertheless continued his march to Constantinople, reaching the Bosphorus in about June and cutting off the capital from Heraclius. Before, the latter had managed to send some horse troops (and written instructions, in which he urged to prepare the fleet for action) as reinforcements. Sahin from Armenia now attempted to drive the emperor’s army west towards Sahrbaraz, but was annihilated in a battle with the Roman forces. Theophanes stated that the emperor’s brother Theodore commanded the imperial army, while Heraclius had returned to Lascia with a small force. Howard-Johnston assumes that the emperor was present with the whole army, and himself commanded it. He thinks that Theophanes is confusing the emperor’s brother with the Saint Theodore, to whose help the victory was later attributed. I found his arguments convincing. He adds that perhaps Heraclius divided his forces after the battle, taking a part of it back to Lascia and leaving a force in Asia Minor under Theodore to keep an eye on Sahrbaraz.

Sahin, grieved by the result of the battle and fearing his master’s anger, committed suicide. By this victory, Heraclius regained the initiative and was able to return to Lascia when the capital weathered the Avar storm, for when the battle was fought the siege was about to begin. It was a risk that Heraclius did not move to its help as the Persians had anticipated; but he knew the strength of Constantinople, and was surely justified by the result.

Constantinople, as it will be remembered, was under the command of Bonos, the population stiffened by Sergios. The available soldiers for its defence, including the last-minute reinforcements, numbered about 12,000 men, perhaps more. The walls had been strengthened, ample provisions (grain now that Egypt was lost came from Africa) had been made. The fleet was strong enough to intercept every attempt to cross the Bosphorus, thereby cutting off the Persians from their comrads-in-arms, for they had not brought with them any naval equipment or boats (the fact gives some strength to the conclusion that they had not really the intention to capture Constantinople themselves, but had made the move out of strategic considerations to compell Heraclius to withdraw). All was well prepared to withstand a siege. The main force of the Avars arrived before the capital by the end of July (the vanguard had arrived a month earlier, beginning a „light“ siege) with a host of nearly 80,000 men, entailing a large train and many siege engines. It is probable that they were quite content that the Persians would not cross, for they intended to reap the harvest alone. They were very confident of success.

After pitching their camps, the Avars attacked on the whole length of the Theodosian Walls on July 31. They were bloodily repulsed, but the attacks from now on would not stop till the end of the siege. On August 2, the Chagan, although still hoping to achieve his goal by his own means, sent note to Sahrbaraz and invited him to despatch at least some of his troops, which would be of great symbolic value. For this some of the crude vessels of the Slavs had succeeded in evading the Roman warships and crossed over to the Persian camp at Chalcedon. Sahrbaraz complied, and some of his soldiers ventured to cross during the night. They were intercepted and destroyed, 4,000 persians are said to have drowned. In the ensuing naval battle the tiny little boats and rafts were send to the botom.

The Chagan then prepared the general all-or-nothing assault. He was in a hurry now for he probably by this time had news of the Roman victory against Sahin. On August 7, the boats reappeared, now carrying an infantry assault force, and attacked the sea walls. Again they were all but slain. The desperate assaults made on the land walls were also beaten back.

The defenders were now greatly encouraged, whereas the Avars became more and more demoralized, and difficulties ensued between the Avars and the Slavs. The troops of Theodore could be awaited to arrive at any time. So during the night the Chagan gave orders to withdraw, and to set fire to the siege train. The next morning they were gone, leaving but smoking ruins behind. Sahrbaraz soon had to do the same, retracing his steps into Syria.

The year ended with the most important results. The threat to Constantinople was over, the might of the Avars broken. Persia had lost an army, and with it one of its best commanders; the other (Sahrbaraz) was grumbling and disaffected with Chosroe, whom he saw as responsible for the disaster. The Romans had regained the initiave, and they had achieved that without losing the positions in Armenia and the Caucasus. Heraclius was already back on his way to Lascia. The main army of Persia was far away, and though intact, had suffered a frustrating reverse and was lead by an disaffected leader. The rest of their forces were scattered, the empire overstretched. The future of Chosroe looked bleak.

III: The Triumph

The Final Campaign (AD 627/628)

Heraclius spent some time negotiating with the Chazars, who had just returned from a raid into Persian territory. At last he succeeded in convincing their chieftain Cebu to lend a hand. The strength of his army at this time is given at 70,000, which again is too high; he had left some troops in Asia Minor, and the reinforcements he was able to get on his way back (a contingent of Armenians came to his colours under their own leader, Georgios) could not have raised his army to this figure.

However high it was, the emperor received reinforcement now from the Chazars, who put forward, we are told, some 40,000 men, again the number seems too high. Nevertheless, the reinforcements must have been substantial. In a later stage these allies left him again, although it seems more probable that this occured only after the end of the campaign, not during it, as it is mentioned by Theophanes. Heraclius was not so successful in convincing the Iberians to follow him; some of their chiefs still supported Persia. Tiflis, where a Persian follower named Stephen resided, had to be taken by force.

The army left the vicinity of Tiflis in September 627, surprising Chosroe with a winter campaign (it was then united again with the forces returned from Asia Minor). Heraclius knew not much of the Persian forces, but he knew that Sahrbaraz was still in the West, not obeying the orders of Chosroe to return. When he had crossed the Araxes, he encountered the only substantial force Chosroe had been able to muster in the region to stop the imperial advance, an army of some 12,000 men (wether this number is accurate is not clear, numbers of 30,000 and even 50,000 men are also mentioned; but it seems more probable that the army was rather small, at least smaller than the emperor’s force; there is also a statement of Theophanes that Chosroe had difficulties maintaining his manpower; this refers to the campaign of 625, but after the loss of Sahin’s army the situation should have been worse in this aspect), commanded by a certain Rhahzadh. I would conclude that this army approached the Araxes from east of Lake Urmia, and was surprised when Heraclius bypassed it by taking the road west of the lake for his new advance south. Heraclius hoped to break through to the Tigris at Niniveh and then to march south on Dastaegard and Ctesiphon to finish the war this time. Rhadzadh meanwhile hurried back to Ganzac, where again he was not in the position to intercept the Romans when they now turned west towards the Greater Zab river and Niniveh. They then had to follow the path of the Romans and could so not prevent them from crossing the mountains and the Zab. When Heraclius stood near Niniveh, the Persians blocked the route south after definite orders of Chosroe to give battle. After a brief respite, Heraclius attacked on December 12, 627. It was a hard going, but finally the enemy gave way, leaving behind many dead on the field, including their general. The remnants fell back on reinforcements sent by Chosroe and continued to harass the Romans but were no longer a serious obstacle to the advance.

After the battle, the Roman soldiers could recuperate a bit, getting rest for some days. Then the march was resumed, south on the east bank of the Tigris. Many palaces of Chosroe and his nobles were destroyed. Dastaegard, the King’s residence, was entered January 4, 628, where many Roman prisoners (and banners) were liberated and much booty was taken. Not even now was Chosroe in a mood to accept the peace proposals of Heraclius. He had fled to his capital, Ctesiphon, assembling there his troops for a last-ditch stand. He did not know that the Emperor had nothing of that kind in mind. The Persian troops in the fortifications of Ctesiphon would be a hard nut to crack, perhaps too hard. Perhaps he still dreaded Sahrbaraz, but it is probable that he was anticipating that this general would do nothing to rescue his king. The main reason why Heraclius now held back and retreated north was another: He was very aware that Chosroe by now was despised not only by large parts of the population and his nobles, but also by the chief ministers and the army. When now the Roman Army would appear at the gates, Chosroe perhaps would be able to rally the discontent to resist the common enemy. In refusing to do so, Heraclius left the king behind sitting in a snake’s nest, and only needed to await developments. It was a clever, if lucky, manoever of much foresight, for in February some secret emmissaries were sent to him by Chosroe’s son Seroe who informed him that he was planning to put himself on the throne and desired peace.

Heraclius then moved back to Ganzac, and in March he received the message that Chosroe had been overthrown (and later killed).

Peace (AD 629)

Heraclius was now ready to dictate terms. His main goal was the restoration of the imperial frontiers from 602 (as guarantied by Chosroe to Maurice in 591), and to get back the Holy Cross. Seroe granted everything, and Heraclius was prudent enough not to weaken Persia beyond that point.

But now there was another development: Sahrbaraz, long nourishing his anger and frustration against the king, reappeared on the scene, and after the death of Seroe (without signs indicating foul play) in September 628 Heraclius supported his grasp for the throne (although Sahrbaraz would not live long to enjoy it). The new king in turn would hold all promises Seroe had made. So the peace treaty was renewed (July 629). Armenia, Syria, Palaestine, Roman Mesopotania and Egypt were restored to the empire, the Holy Cross handed over to the Roman emissaries. Heraclius himself brought it back to Jerusalem after an enthusiastic welcome in Constantinople. The war was over, won at last.

I think Treadgold is very right in his conclusion that „Heraclius’s nerve and strategic sense deserves much, probably most, of the credit“ for the „miraclious“ saving of the Empire. Though much of the provinces he brought back under Roman sway would be lost to the Arabs just a few years later, his achievements in this war were great: He restored the tottering empire, laid the roots for sorely needed reforms which would transform the whole empire and gave it the strength to survive future crises, and at length to recover some of the territory and to break the Arabian power. But this is a story not to be told here.