The mighty Persian
Empire, or as the Romans
called them, the Parthians
, were a constant "thorn in the side" of Empires, from the Greek Empire
, to the Roman Empire
and the Byzantine Empire
. In A.D. 436, the Western Roman Empire collapsed
in a wave of barbarian
invasions. The Visigoths
poured into Italy
and the northern frontiers
, and eventually, in A.D. 476, marched on and sacked Rome
. The Parthians now saw an oppurtunity to take the crumbling Empire for themselves, but the Byzantines
had similar ambitions.
Thus, the two Empires left at this stage were very soon to be brought into conflict. The First Byzantine-Persian War erupted in A.D. 502 when diplomatic relations between Emperor Justinian and King Kavad of Parthia broke down. Kavad was overconfident and only sent a small force into the province of Armenia. Despite this, the Byzantines were defeated at Amida, and Kavad pushed through to Trebizond, then sent another army down through the province of Cilicia to take Callinicum. These defeats were largely due to the fact that Byzantium's armies were fighting in North Africa to reclaim the Empire, and Justinian did not want them to be diverted. Instead of continuing the war, he approached Kavad in A.D. 506 with an offer of a treaty and 11,000 pounds of gold, on the condition that all the recent conquests be ceded back to Byzantium. Kavad agreed and the First Byzantine-Persian War was over.
An ambitious Byzantine noble known as Belisarius approached the Justinian and requested he be tasked with recapturing Rome, as was part of his plan to restore the Empire. Although, Justinian was preoccupied with fighting in Spain and Northern Africa, and so only partially supported Belisarius, awarding him nothing more than 5000 Hunnish and Moorish auxilaries. Belisarius marched on Rome, regardless, but he did not even have a full banda (Byzantine equivalent of a legion), and the Emperor had refused to allow him access to any of the more elite Byzantine troops such as Byzantine Infantry or Kataphraktoi.
In A.D. 536 Belisarius reached Naples, and now had the task of subjugating the southern province before he could march on Rome. With only 5000 men, Belisarius tried to approach the citizens of the city of Naples and request their peaceful submission, they refused and so Belisarius began besieging the city. The siege lasted months, and skirmishes were wearing out his troops, and were it not for a broken aqueduct, found by a scout, that lead through the city wall, the battle may not have been won. Belisarius consolidated the province, the marched to Rome, where the citizens opened the gates, and the defending Goths were defeated. Belisarius now had the task of fortifying a circuit wall 12 miles in diamater with only 5000 troops, and was expecting an army to show up that outnumbered him more than 10 to 1.
The army of Visigoths and Ostrogoths reached Rome in A.D. 537 and surrounded the city, but they were defeated, despite their vast numerical superiority. With Rome under control, Justinian now vested more interest in Belisarias, and he sent reenforcements; the entire Italian peninsular was conquered. The fighting in North Africa and Spain had gone well also, and Justinian had taken up to Cordoba. The Byzantines were at their highest point, but it was about to plummet back down again. First the Arabian tribes, converting to Islam, rebelled and waged war against Byzantium, then the Parthians, taking advantage of the fact that Byzantium's armies were far off, sent their armies to spead over the entire Mesopotamian (mid-East) region. Justinian pulled troops away from Spain, Africa and Italy, believing them to be safe in the meantime, and sent them into Parthia with Belisarius at their command. The Second Byzantine-Persian War had begun in A.D. 527.
Kavad was, again, overconfident, and he believed that he would easily defeat the Byzantines in Mesopotamia, and so he sent a sizable force to invade Byzantium's holdings in Spain. Here the Parthians were successful, pushing the Byzantines from Spain by A.D. 528, however by this stage Belisarias had driven far into Parthia itself, and won a key battle at Darsas, but was then defeated at the nearby city of Callinicum in A.D. 531. Despite this defeat, the Battle of Callinicum is far more important than the battle of Darsas, as Kavad was killed in battle here, and the Parthians were divided by civil war. Khusaru, Kavad's son, had to contend with the usurper Mazdak, and so the Byzantines had the chance to withdraw and fortify the border. Khusaru was victorius, and in the same year Mazdak and his followers were caught and executed for treason. After this Khusaru withdrew from Spain and approached Justinian and signed a peace treaty in perpetuum (forever). Spain was reinvaded and reclaimed in A.D. 535
This treaty was not to last, however, as in A.D. 540 Khusaru, angered by Justinian's religious policies, invaded Syria and sacked Antioch. Justinian, still wishing for peace, hastily signed a treaty, but the Parthians began extorting Byzantine cities, and Justinian once again diverted troops to handle the Parthians. Once again, the Parthians invaded Spain, taking Lazica in A.D. 541. The Byzantines reclaimed Syria, and the Parthians invaded Edessa in A.D. 544, but were unsuccesful in besieging it. Moving their troops to the offensive, pushing the Parthians back out of Mesopotamia and besieging Lazica. Justinian demanded a truce, and a five year cease fire was signed, but this was only a maneuver by Justinian to gain time. In A.D. 548, with one year left, the Byzantines invaded Lazica, conquering it once again, and repelled the Parthian's attacks on the border to Mesopotamia.
Fighting over Lazica continued for the next seven years, and both armies were wearying by this stage, but the Byzantines had a slight upper hand, and forced the Parthians into a fifty year peace. The Parthians withdrew from Spain and Lazica was recognised as a Byzantine city for an annual tribute. This peace was not to last either, however, and in A.D. 572, the Armenians revolted under their new Emperor Justinan II. The Byzantines reclaimed the province, but then continued to march into Parthia. The Parthians fought back, pushing the Byzantines out and back to Trebizond. The Parthians ravaged Syria, and then the Byzantines made another offensive in A.D. 579. Khusaru was killed in this offensive, and an uneasy treaty was signed yet again. This was the end of the Second Byzantine-Persian War.
This peace lasted longer than the others, though it was not permanent. In the years after the second war, many African provinces had rebelled, and most of Italy had been lost to the Ostrogoths. The Byzantine armies had been weakened trying to supress these revolts, and in A.D. 603 King Khosroes of Parthia took advantage of this and began a march through Byzantine territory, marking the beginning of the Third Byzantine-Persian War. The current Emperor was Phocas, and he hardly opposed the invasions. By A.D. 607 the Byzantines had lost Armenia, Kappadocia, Galatia, and Paphlagonia. By A.D. 610 the Parthians had further advanced into Syria, Palestine, Phoenicia, Chalcedon, Apamea, Edessa and finally Antioch. It was in this year that Emperor Phocas died, and Emperor Heraclius took the throne. Heraclius was unwilling to tolerate the Parthians.
In A.D. 611 he began planning for an offensive, but the Parthians beat him to it, capturing Kappadocian Caesarea and many prisoners from the army along with it. The Parthians ransomed many of them back, but in a horrid turn of luck the Avars began invading Bulgaria in this same year, marking the start of the Byzantine-Avar War. Heraclius diverted most of the army to Bulgaria, ending the war there by A.D. 613. He then surveyed the army, and realized that there were only two bandas at full strength. Byzantium could not combat the Parthians at this stage, and so he sent diplomats to negotiate a cease fire with them. They were turned away, however, and by A.D. 619 Egypt, Ethiopia, Libya and Carthage fell to the Parthians. Byzantium had lost all its African and Italian holdings now, its corn supply had been disrupted, and it was prime for conquering. Although Heraclius bided his time, and rather than feebly attempting to defend his lands with a small, wearied army, he held them back and began reforming the army.
The Parthians now were met with trouble. The provinces they had just conquered were largely christian or eastern orthodox, and were quite resilient to their pagan rule. Thus, they were forced to spend time consolidating, when they otherwise could have made the final strike at Byzantium. In the meantime, Heraclius had strengthened the army, and in A.D. 621 prepared to make an offensive against the Parthians. He began promoting himself as a christ figure, and had the troops blessed. The invasion that was about to commence was, in a sense, a Crusade to reclaim the Holy Lands. Heraclius recruited many Byzantine Infantry, took charge of the army himself and brought with him Kataphraktoi. These units were elite, and vastly superior in technology to the Parthian troops. The Byzantine army was in high morale and had a burning religious ambition to regain these lands, thus the Byzantines seemed to have the upper hand now.
The war began in the Spring of A.D. 621 with the invasion of Edessa. By the winter of A.D. 622 the Byzantines had reclaimed Antioch, Armenia and Albania. They set up winter camp here, in Albania, and with the newly enlargened army (many freed prisoners joined the "crusaders") he blessed the entire army once more. The offensive was renewed in Spring, and they continued to march towards Jerusalem. By A.D. 626 the Byzantines had reclaimed all their lost provinces save for Palestine and the African provinces. They were held on the border of Palestine with heavy battle, but the African provinces then rebelled against the Parthians, causing them to divert troops to deal with them. The Byzantines broke through and marched onwards towards Jerusalem, and the Parthian army was defeated by the African rebels. The final battle was fought at Jerusalem in A.D. 630, and the Parthians were defeated. The victorius "crusaders" replaced the Holy Cross at Jerusalem, which had been taken by the Parthians. The Third Byzantine-Persian War was over, and the Byzantines now turned to reclaiming their African provinces.
Here the Byzantines were halted, however, as Islam was making a true rise in the East, and they had to turn inwards. Soon after this, the Turks arrived in the East, and the Byzantines lost much of their territory. The Parthian Empire was no longer bordering with the Byzantines, as the Turks laid in between the two, and the Byzantine-Persian Wars were over for good.