Roman – Parthian War of 58 – 63 The Roman – Parthian War of 58 – 63 was fought between the Roman Empire and the Parthian Empire over control of Armenia , a vital buffer state between the two realms . Armenia had been a Roman client state since the days of Emperor Augustus , but in 52 / 53 , the Parthians succeeded in installing their own candidate , Tiridates , on the Armenian throne . These events coincided with the accession of Nero to the imperial throne in Rome , and the young emperor decided to react vigorously . The war , which was the only major foreign campaign of his reign , began with rapid success for the Roman forces , led by the able general Gnaeus Domitius Corbulo . They overcame the forces loyal to Tiridates , installed their own candidate , Tigranes VI , on the Armenian throne , and left the country . The Romans were aided by the fact that the Parthian king Vologases was embroiled in the suppression of a series of revolts in his own country . As soon as these had been dealt with , however , the Parthians turned their attention to Armenia , and after a couple of years of inconclusive campaigning , inflicted a heavy defeat on the Romans in the Battle of Rhandeia . The conflict ended soon after , in an effective stalemate and a formal compromise : a Parthian prince of the Arsacid line would henceforth sit on the Armenian throne , but his nomination had to be approved by the Roman emperor . This conflict was the first direct confrontation between Parthia and the Romans since Crassus ' disastrous expedition and Mark Antony ' s campaigns a century earlier , and would be the first of a long series of wars between Rome and Iranian powers over Armenia ( see Roman – Persian Wars ) . Background . Ever since the expanding Roman Republic and the Parthian Empire had come into contact in the mid - 1st century BC , there had been friction between the two great powers over the control of the various states lying between them . The largest and most important of these was the Kingdom of Armenia . In 20 BC , Augustus succeeded in establishing a Roman protectorate over the country , when Tigranes III was enthroned as king of Armenia . Roman influence was secured through a series of Roman - sponsored kings until 37 AD , when a Parthian - supported candidate , Orodes , assumed the throne . The Roman - supported king , Mithridates , recovered his throne with the support of Emperor Claudius in 42 AD , but was deposed in 51 AD by his nephew Rhadamistus of Iberia . His rule quickly became unpopular however , and this gave the newly crowned king Vologases I of Parthia the opportunity to intervene . His forces quickly seized the two capitals of Armenia , Artaxata and Tigranocerta , and put his younger brother Tiridates on the throne . The onset of a bitter winter and the outbreak of an epidemic forced the Parthians forces to withdraw , allowing Rhadamistus to retake control of the country . His behavior towards his subjects , however , was even worse than before , and they rose in rebellion against him . Thus in 54 AD Rhadamistus fled to his father ' s court in Iberia , and Tiridates re - established himself in Armenia . In the same year , in Rome , Emperor Claudius died and was succeeded by his stepson Nero . The Parthian encroachment in an area regarded as lying within the Roman sphere of influence worried the Roman leadership , and was widely seen as a major test of the new emperor ' s ability . Nero reacted vigorously , appointing Gnaeus Domitius Corbulo , a general who had distinguished himself in Germania and now served as governor of Asia , to supreme command in the East . Diplomatic maneuvers and preparations . Corbulo was given control over two provinces , Cappadocia and Galatia ( modern - day central Turkey ) , with propraetor ial and later proconsular authority or " imperium " . Although Galatia was considered a good recruiting - ground and Cappadocia had a few units of auxiliaries , the bulk of his army came from Syria , where half the garrison of four legions and several units of auxiliaries was transferred to his command . Initially , the Romans hoped to resolve the situation by diplomatic means : Corbulo and Ummidius Quadratus , the governor of Syria , both sent embassies to Vologases , proposing that he give up hostages , as was customary during negotiations , to ensure good faith . Vologases , himself preoccupied by the revolt of his son Vardanes which forced him to withdrew his troops from Armenia , readily complied . A period of inactivity ensued , while the Armenian issue remained in limbo . Corbulo used this lull to restore his troops ' discipline and combat readiness , which had diminished in the peaceful garrisons of the East . According to Tacitus , Corbulo discharged all who were old or in ill health , kept the entire army under canvas in the harsh winters of the Anatolian plateau to acclimatize them to the snows of Armenia , and enforced a strict discipline , punishing deserters by death . At the same time however , he took care to be constantly present amongst his men , sharing their hardships . In the meantime , Tiridates , backed by his brother , refused to go to Rome , and even engaged in operations against those Armenians whom he deemed were loyal to Rome . Tension mounted and finally , in the early spring of 58 , war broke out . Outbreak of the war — The Roman offensive . Corbulo had placed a large number of his auxiliaries in a line of forts near the Armenian frontier under a former " primus pilus " , Paccius Orfitus . Disobeying Corbulo ' s orders , he used some newly arrived auxiliary cavalry " alae " to stage a raid against the Armenians , who appeared to be unprepared . In the event , his raid failed , and the retreating troops even spread their panic amongst the garrisons of the other forts . It was an inauspicious start for a campaign , and Corbulo severely punished the survivors and their commanders . Having drilled his army for two years Corbulo , despite this misadventure , was ready . He had three legions at his disposal ( III " Gallica " and VI " Ferrata " from Syria and IV " Scythica " ) , to which were added a large number of auxiliaries and allied contingents from Eastern client kings like Aristobulus of Lesser Armenia and Polemon II of Pontus . The situation was furthermore favorable to the Romans : Vologases faced a serious revolt by the Hyrcania ns in the region of the Caspian Sea as well as incursions of Dahae and Sacae nomads from Central Asia , and was unable to support his brother . The war thus far had featured mostly skirmishing along the Roman – Armenian border . Corbulo tried to protect the pro - Roman Armenian settlements from attack , and simultaneously retaliated against the Parthians ' supporters . Given that Tiridates avoided confrontation in a pitched battle , Corbulo divided his force , so that they could attack several places simultaneously , and instructed his allies , Kings Antiochus IV of Commagene and Pharasmanes I of Iberia to raid Armenia from their own territories . In addition , an alliance was concluded with the Moschoi , a tribe living in northwestern Armenia . Tiridates reacted by sending envoys to ask why he was under attack , since hostages had been given . To this , Corbulo reiterated the demand to seek the recognition of his crown from Nero . Eventually , the two sides agreed on a meeting . Tiridates announced that he would bring 1 , 000 men to the meeting , implying that Corbulo should bring the same number of men " in peaceful fashion , without breastplates and helmets " . Tacitus suggests that Tiridates intended to overwhelm the Romans , as the Parthian cavalry would be superior to an equal number of Roman infantry in any case . At any rate , in a show of force Corbulo decided to take with him the larger part of his force , not only IV " Ferrata " , but also 3 , 000 men from III " Gallica " plus the auxiliaries . Tiridates also appeared at the agreed site , but , seeing the Romans in full battle array , and in turn distrusting their intentions , he did not come closer and withdrew during the night . Tiridates then resorted to a tactic that had worked well a century earlier against Mark Antony : he sent forces to raid the Roman army ' s supply route , which stretched over the mountains back to Trapezus in the Black Sea . They failed however , since the Romans had taken care to secure the mountain routes by a series of forts . Fall of Artaxata . Corbulo now resolved to directly attack Tiridates ' fortified strongholds . Not only were they instrumental in controlling the surrounding country and sources of revenue and soldiers , but in addition , a threat to them might force Tiridates to risk a pitched battle , since , in the words of historian A . Goldsworthy , " a king who could not defend communities loyal to him [ . . . ] lost prestige . " Corbulo and his subordinates successfully stormed three of these forts , including Volandum ( possibly modern Iğdır ) , " the strongest of all in that province " according to Tacitus , within a day with minimal casualties , and massacred their garrisons . Terrified by this display of Roman might , several towns and villages surrendered , and the Romans prepared to move against the northern Armenian capital , Artaxata . This forced Tiridates to confront the Romans with his army , as they approached Artaxata . The Roman force , reinforced by a " vexillatio " of X " Fretensis " , marched in a hollow square , with the legions supported by auxiliary horsemen and foot archers . The Roman soldiers were under strict orders not to break formation , and despite repeated probing attacks and feigned retreats by the Parthian horse archers , they held together until nightfall . During the night , Tiridates withdrew his army , abandoning his capital ; its inhabitants promptly surrendered and were allowed to leave unmolested , but the city was torched , since the Romans could not spare sufficient men for garrisoning it . Fall of Tigranocerta . In 59 , the Romans marched to the south , towards Tigranocerta , Armenia ' s second capital city . On their way , Corbulo ' s men punished those who withstood or hid from them , while leniency was shown to those who surrendered . In the harsh , dry terrain of northern Mesopotamia , the army suffered from lack of provisions , especially water , until they reached the more fertile areas near Tigranocerta . During that time , a plot to murder Corbulo was uncovered and suppressed . Several Armenian nobles who had joined the Roman camp were implicated and executed . According to a story provided by Frontinus , when the Roman army arrived at Tigranocerta , they launched the severed head of one of the conspirators into the city . By chance , it landed right where the city council was assembled ; they immediately decided to surrender the city , which was consequently spared . Shortly after , an attempt by the Parthian army under king Vologases to enter Armenia was blocked by Verulanus Severus , the commander of the auxiliaries . The Romans were now in control of Armenia , and they promptly installed its new king , Tigranes VI , the last descendant of the Cappadocian royal house , in Tigranocerta . Some outlying western parts of Armenia were also ceded to the Roman vassals . Corbulo left 1 , 000 legionaries , three auxiliary cohort s and two cavalry " alae " ( ca . 3 - 4 , 000 men ) behind to support the new monarch , and retired with the rest of his army to Syria , whose governorship he now ( in 60 AD ) assumed as a reward for his success . Parthian counterattack . The Romans were well aware that their victory was still fragile , and that as soon as the Parthian king had dealt with the Hyrcanian rebellion , he would turn his attention to Armenia . Despite Vologases ' reluctance to risk an all - out conflict with Rome , in the end , he was forced to act when Tigranes raided the Parthian province of Adiabene in 61 . The enraged protests of its governor Monobazus , and his pleas for protection , could not be ignored by Vologases , whose prestige and royal authority were at stake . Vologases therefore hastily concluded a treaty with the Hyrcanians so as to be free to campaign against Rome , and called an assembly of the grandees of his realm . There he publicly reaffirmed Tiridates ' position as king of Armenia by crowning him with a diadem . In order to reinstall his brother on the Armenian throne , the Parthian king assembled a force of picked cavalry under Monaeses , complemented by infantry from Adiabene . In response , Corbulo sent the legions IV " Scythica " and XII " Fulminata " to Armenia , while he detailed the three other legions under his command ( III " Gallica " , VI " Ferrata " and XV " Apollinaris " ) to fortify the line of the river Euphrates , fearing that the Parthians might invade Syria . At the same time , he petitioned Nero to appoint a separate legate for Cappadocia , with the responsibility for conducting the war in Armenia . Parthian siege of Tigranocerta . Monaeses meanwhile entered Armenia and approached Tigranocerta . Tigranes had taken care to gather supplies , and the city was well - fortified and garrisoned with Romans and Armenians alike . The siege was largely undertaken by the Adiabenian contingent , since the Parthians , being cavalrymen , were unskilled and unwilling to engage in siegework . The Parthian assault failed , and was driven back with loss by a successful Roman sally . At this point , Corbulo sent an envoy to Vologases , who had encamped with his court at Nisibis , near Tigranocerta and the Roman – Parthian border . The failed siege and a shortage of fodder for his cavalry forced Vologases to agree to withdraw Monaeses from Armenia . At the same time however , the Romans too left Armenia , something that , according to Tacitus , raised suspicions of Corbulo ' s motives : some whispered that he had reached an agreement of mutual withdrawal with the Parthians , and that he was unwilling to risk his reputation by renewing hostilities against them . At any rate , a truce was arranged and a Parthian embassy was dispatched to Rome . The negotiations failed to reach an agreement , and war was resumed in the spring of 62 . In the meantime , the asked - for legate for Cappadocia had arrived , in the person of Lucius Caesennius Paetus , the consul of the previous year ( 61 AD ) . The army was divided between him and Corbulo , with IV " Scythica " , XII " Fulminata " , the newly arrived V " Macedonica " and the auxiliaries from Pontus , Galatia and Cappadocia going to Paetus , while Corbulo retained III " Gallica " , VI " Ferrata " and X " Fretensis " . Because of their antagonism for glory , the relations between the two Roman commanders were strained from the beginning . It is notable that Corbulo kept the legions he had spent the past few years campaigning with , and gave his colleague , who after all was expected to conduct the main campaign , the more inexperienced units . The total Roman force arrayed against the Parthians was nevertheless considerable : the six legions alone totaled some 30 , 000 men . The exact number and disposition of auxiliary units is unclear , but there were seven cavalry " alae " and seven infantry cohorts in Syria alone , comprising a force of 7 - 9 , 000 troops . Battle of Rhandeia . Paetus nonetheless appeared confident of victory , and followed the Parthian declaration of war and capture of Tigranocerta with his own invasion of Armenia , while Corbulo remained at Syria , further strengthening the fortifications in the Euphrates frontier . Paetus had only two legions with him , IV " Scythica " and XII " Fulminata " , and advanced towards Tigranocerta . A few minor forts were taken , but a lack of supplies forced him to withdraw westwards for the winter . The Parthians had originally intended to invade Syria , but Corbulo put on a convincing display of military might , building a strong flotilla of ships equipped with catapult s and a bridge over the Euphrates , which allowed him to establish a foothold on the Parthian shore . Therefore the Parthians abandoned their plans for Syria , and turned their attention towards Armenia . There , Paetus had dispersed his forces and granted extended leaves to his officers , so that he was taken unawares at the Parthian advance . Upon learning of it , he initially advanced to meet Vologases , but after a reconnaissance detachment was defeated , he panicked and withdrew hastily . Paetus sent his wife and son to safety in the fortress of Arsamosata , and tried to block the Parthian advance by occupying the passes of the Taurus mountains with detachments from his army . In so doing , however , he further dispersed his forces , which were then defeated in detail by the Parthians . Roman morale plunged and panic set in among the army , which was now besieged in a series of hastily erected camps near Rhandeia . Paetus , who appears to have fallen into desperate inactivity , sent urgent messages to Corbulo to come to his rescue . Corbulo in the meantime had been aware of the danger faced by his colleague , and put part of his forces on readiness ; but he did not march to join Paetus , and some accused him of delaying in order to reap more glory from rescuing him . Nevertheless , when the calls for assistance arrived , he responded quickly and marched forth with half of the Syrian army , carrying many provisions laden on camels . He soon met dispersed men of Paetus ' army , and managed to rally them around his force . But before he could arrive to the rescue , Paetus had capitulated : the Parthians , aware that relief was nearing , increasingly harassed the Romans , until Paetus was forced to send a letter to Vologases to seek terms . The subsequent treaty was humiliating : not only would the Romans leave Armenia and surrender all forts they held , but they also agreed to build a bridge over the nearby Arsanias river over which Vologases could pass in triumph , sitting atop an elephant . In addition , the Roman army was liberally plundered by the Armenians , who took even the Romans ' weapons and clothes without facing any resistance . Still worse , according to rumors reported by Tacitus , the Romans were made to pass under the yoke , a gesture of ultimate humiliation in Roman eyes . The two Roman forces met on the banks of the Euphrates near Melitene , amidst scenes of mutual grief ; while Corbulo lamented the undoing of his achievements , Paetus tried to convince him to attempt to reverse the situation by invading Armenia . Corbulo however refused , claiming that he did not have the authority to do so , and that either way the army was too worn out to be able to campaign effectively . In the end , Paetus retired to Cappadocia and Corbulo to Syria , where he received envoys from Vologases , who demanded that he evacuate his bridgehead over the Euphrates . In turn , Corbulo demanded the Parthian evacuation of Armenia . Vologases agreed to this , and both sides withdrew their forces , leaving Armenia once again masterless but " de facto " under Parthian control , until a Parthian delegation could travel to Rome . Corbulo ' s return and peace settlement . Rome , meanwhile , appears to have been largely unaware of the real situation in Armenia . Tacitus acidly records that " trophies for the Parthian war and arches were erected in the center of the Capitoline hill " by decree of the Senate , even while the war was not yet decided . Whatever illusions the Roman leadership had , they were shattered by the arrival of the Parthian delegation to Rome in the spring of 63 . Their demands , and the subsequent interrogation of the centurion who accompanied them , revealed to Nero and the Senate the true extent of the disaster , which Paetus had concealed in his dispatches . Nevertheless , in the words of Tacitus , the Romans decided to " accept a dangerous war over a disgraceful peace " ; Paetus was recalled , and Corbulo placed again in charge of the campaign into Armenia , with extraordinary " imperium " which placed him above all other governors and client rulers in the East . Corbulo ' s post as governor of Syria was entrusted to Gaius Cestius Gallus . Corbulo reordered his forces , withdrawing the defeated and demoralized IV " Scythica " and XII " Fulminata " legions to Syria , leaving X " Fretensis " to guard Cappadocia , and leading his veteran III " Gallica " and VI " Ferrata " to Melitene , where the invasion army was to be assembled . To these he also added V " Macedonica " , which had remained in Pontus throughout the previous year and not been tainted by the defeat , the newly arrived XV " Apollinaris " , and large numbers of auxiliaries and contingents of the client kings . After his army crossed the Euphrates , following a route opened up by Lucullus over a hundred years before , he received envoys from Tiridates and Vologases . At the approach of such a large force , and aware of Corbulo ' s ability as a general , the two Arsacids were anxious to negotiate . Indeed , Corbulo , no doubt on instructions from Nero , reiterated the old Roman position : if Tiridates would accept his crown from Rome , then renewed war could be averted . Tiridates readily agreed to negotiations , and Rhandeia , the scene of last year ' s Roman defeat , was agreed upon as a meeting place . To the Armenians , this place was intended as a reminder of their strength , while Corbulo agreed to it because there he hoped to expunge the earlier disgrace , by peace or war . Once there , Corbulo put Paetus ' son , who served under him as a legate , in charge of a party that was to gather the remains of the Roman soldiers and ensure them a proper burial . On the agreed day , both Tiridates and Corbulo , each accompanied by 20 horsemen , met between the two camps . Tiridates agreed to travel to Rome and seek confirmation of his crown from Nero . In sign of this agreement , a few days later , both armies put on a display , arrayed in full parade gear . Tiridates approached the Roman camp , where a statue of the Emperor Nero had been erected upon a raised platform , and placed his royal diadem at its feet in submission . Aftermath . In 66 , Tiridates visited Rome to receive his crown and was lavishly received by Nero , who used the occasion to boost his own popularity . He ordered the gates of the Temple of Janus to be shut , thus declaring that peace reigned throughout the Roman Empire . Nero celebrated this peace as a major achievement : he was hailed as " imperator " and held a triumph , although no new territory had been won , and the peace reflected a compromise rather than a true victory . For although Rome could prevail militarily in Armenia , politically , she had no genuine alternatives to the Arsacid candidacy on offer for the Armenian throne . Armenia would henceforth be ruled by an Iranian dynasty , and despite its nominal allegiance to Rome , it would come under increasing Parthian influence . In the judgment of later generations , " Nero had lost Armenia " , and although the Peace of Rhandeia ushered in a period of relatively peaceful relations that would last for 50 years , Armenia would continue to be a constant bone of contention between the Romans , the Parthians , and their Sassanid successors . For the short term however , the peace that Nero secured was kept by both sides , even while the bulk of Rome ' s eastern forces was involved in the suppression of the Jewish Revolt . As for Corbulo , he was honoured by Nero as the man who had brought this " triumph " to be , but his popularity and influence with the army made him a potential rival . Together with the involvement of his son - in - law Lucius Annius Vinicianus in a foiled plot against Nero in 66 , Corbulo became suspect in the eyes of the emperor . In 67 , while journeying in Greece , Nero ordered him to be executed ; upon hearing of this , Corbulo committed suicide . This parthian war had also demonstrated to the Romans that the defensive system in the East , as put in place by Augustus , was no longer adequate . Thus the following years saw a major reorganization of the Roman East : the client kingdoms of Pontus and Colchis ( in 64 AD ) , Cilicia , Commagene and Lesser Armenia ( in 72 AD ) were made into Roman provinces , the number of legions in the area increased , and Roman presence in the Caucasian client states of Iberia and Albania strengthened , with the aim of strategically encircling Armenia . Direct Roman control was extended to the entire line of the Euphrates , marking the beginning of the Eastern " limes " that would survive until the Muslim conquests of the 7th century .