The fifth Eftal Shah
The end of the Akhshunwarid Dynasty and the ascendency of Mihiragula marks the beginning of the end of the chaos and transition which marked the reign of his predecessors. He maintained relative peace along the long, steppe border by choosing to continue to honor pacts made with the Celestial Tujue. This period of peace allowed for trade of both commerce and ideas with China and India.
The Gupta continued to preside over a golden age of art and culture even as their Empire collapsed and was reduced to a still-potent but much reduced regional power along the Ganges. Their decline paved the way for the era of the Kalachuri and the Vakataka along the coast, now freed from Gupta influence. Stone-cut Takasashila, still a great center of learning and Buddhist civilization was freed from the Gupta Empire in this period by an uprising which saw Gandhara ruled from Purushapura once more. The ruling dynasty, called the Johiyava Rajas seems to have had good relations with the Eftal, exchanging hostages and trade. The Johiyava developed a reputation as a warrior people and as patrons of Hinduism, and from time to time feuded with the Rai dynasty to their south and the Arjunayanas.
Meanwhile, the Western borders were far less peaceful. The Roman Empire was holding itself together but at increasing expense, her population only just beginning to recover from the plague. The Bulgar Samur Khan and the Langobard King
Alboin were both now technically "allies" of Emperor Zeno, but the Balkans had not come under this great of a threat since the days of the Goths - and the Imperial diplomats were working overtime, trying to sew tensions between the patchwork confederations of tribes at their gates. This was perhaps far more successful than swords had been - the Utigurs invaded the territories of their kin and the resulting war would distract both parties. Meanwhile, certain nobles amongst the Langobards were elevated in status and formally given large estates in Dalmatia, a move intended to direct their loyalty more directly towards the Empire.
Seeking to restore the East to some measure of stability, the Roman Emperor began to work with King Anastas of Armenia, bringing order to the Caucasus and putting an end to Alan raids. The Emperor's niece married the son of King Anastas, and the Empire financed a joint fortification project.
Fearing that Armenia would fall into the hands of the Romans, Mihiragula had no choice but to begin to prepare for war. A successful war against the Romans would also solidify his legitimacy as Shah, and even an unsuccessful campaign would allow him opportunities to conveniently dispose of those who might still be loyal to Akhshunwar II. Striking secret pacts with the Alans and also a confederation of Arabian tribes, the Kindah, who would oppose the Banu Ghassan, Mihiragula went to war with the Romans in 559, not giving the Empire any time to catch its breath after the bloody wars in the Balkans.
Mihiragula set forth from Nisibin, and unlike his predecessors, he was triumphant, capturing Hierapolis and Edessa and striking into the very heart of the Empire.
To look at the reasons for his successes, it may help to look at the reasons previous Eftal Shahs failed. Akhshunwar was ruler of a vast territory only recently conquered, and his tribal army was not able to translate successful field battles into major gains of territory. Khauwashta faced a capable Roman army under a group of brilliant commanders. Mihiragula, by contrast, had a well-established state and a capable army, veterans of warfare on the eastern steppe. Many of the men under him had fought under Khauwashta as well, and Mihiragula was, if not a warrior like Khauwashta, a tactician and a statesman who could bring together the disparate peoples under his command into an effective fighting force.
Meanwhile, in the south Kindah would see few successes in their raids - they were on the decline by the late sixth century, but managed quite capably to disrupt the overland caravan trade between the Roman world and Arabia - concentrating this trade in the hands of the southern Arabians and their associated maritime city-states.
Third Eftal-Roman War
The Roman state, despite its exhaustion refused to give up without a fight. The eastern frontier troops proved ineffective at stopping the incursion of Mihiragula, despite their successes in preventing further Alan incursions into Asia Minor. The Eftal army enjoyed a series of easy victories and captured or extorted tribute from many cities in Syria and along the Euphrates. Then, Mihiragula swept south and met the Romans in battle at Pagrai. Here, the Roman army was utterly destroyed and the Eftal given "free license to do what they would with the whole of the Orient."
Antiokheia, a city in decline ever since the 526 earthquake, was taken shortly after Pagrai, a short siege ended by Iranian siege engineers. Mihiragula presided over a devastating sack, wherein many relics and great works of art were either captured or destroyed, and the city's already declining population massacred. Riding north, Mihiragula earned through diplomacy and overwhelming force the submission of the Cilician plain and crucially, the city of Tarsus.
A Roman army under the command of one of Hadrianus' former subordinates, Serenos, was sent into Asia Minor with a fresh army, veterans of the Balkan wars mixed with raw recruits. Serenos took a northerly route, hoping to link up with an Armenian army and force Mihiragula to commit troops further north, ideally granting time for the Romans to retake Syria. However, this plan failed. King Anastas was defeated by a General named Hiramaosha at the battle of Zarisat, and when the news reached Serenos he stalled, allowing Mihiragula to meet him in battle outside of Caesarea and, with that triumphant victory, Asia Minor lay open to the Eftal.
By spring 561, the Eftal had raided as far as Nikaia, devastating the Anatolian plateau and wreaking havoc. Around this time, Zeno II was deposed in a coup orchestrated by one Kallinikos, a Greek military officer who had served with distinction in a time where few officers had. Ruling as Flavius Callinicus Augustus, he was an active Emperor, spending much of his time personally ensuring the defenses of cities in Asia Minor. Still, it would take Kallinikos time to truly command the apparatus of state - having come to power in a coup, he was forced to move carefully and establish himself as a defender of Christendom from the pagan hordes, no matter how nuanced the reality of the situation was.
What he could not do is save the Orient. Mihiragula rode south, leaving Hiramaosha to oversee the raiding of Asia and vex the reformed Roman field armies there. Hiramaosha proved more than capable at this task, but ultimately was slowly forced back by Kallinikos, who personally led the Roman armies and pushed Hiramaosha back to Caesarea. Damascus fell easily, and after a long siege, Jerusalem was taken in January of 562.
The shock throughout the Roman world was immense. As one Roman playwright wrote, "Holy Jerusalem has fallen! Weep for all the generations of Christians, weep for the martyrs. The Hun have destroyed the object of all our vows. The Heavenly City lies destroyed." Exaggerated tales of massacres were spread, but in truth it seems that the region was not heavily depopulated, in contrast to the annihilation of Antioch - although the Patriarch was, according to our Greek sources, killed, and many holy relics taken as trophies of war.
Mihiragula, after erecting a great monument to his victory, praised both Shiva and Mithra for delivering him the victory, but his language was not one of religious war. The victory monument lists Jerusalem as one of many cities taken, and while he must have known the effect its conquest would have on his enemies, for him his war was an explicitly political one. By contrast, Kallinikos was whipping the Roman Empire into a religious frenzy. The heathen was at the gates, the vicious Huns stood poised to annihilate the very Empire.
Mihiragula would reach as far south as Gaza before turning north once more. Egypt, despite not having large armies at its disposal, was a tough nut to crack in the best of times, and attempts by the Eftal to encourage a popular uprising seem to have enjoyed little success.
Of course, the Eftal possessed no way to cross into Europe, and by the time Mihiragula linked up with Hiramaosha (leaving his new conquests under the often-feeble control of Persian garrison troops and new made local administrators), the Shah was on the back foot. Attacking deep into the Asia Minor three more times between 562 and 565, each time was met with less success - the Roman war machine remained capable and despite a series of brutal famines, there was no rioting in Constantinople or the provinces, and the Romans enjoyed victories as often as they suffered defeats.
A Roman embassy in 565 nearly achieved peace, but for Mihiragula's confidence in his ability to push on. Nearly his entire reign had been spent at war, and he had, at least on paper, enlarged and restored the Eftal Empire. Reincorporating Armenia as a vassal state after her King's crushing defeat and conquering the Orient had assured him of his invincibility. The tribute he demanded was crushing and utterly unrealistic, and Mihiragula expected to retain all of his tremendous territorial gains. Unwilling and quite likely politically unable to concede Jerusalem or allow the Empire to be severed and drained of all her incomes, Kallinikos had little choice but to fight on.
Mauri Africa and the Goths - the Western Mediterranean
While what remained of Rome burned, her heirs rose in power and prestige. Their merchants re-established old trade links and it seems that the coastal cities were some of the quickest to recover, even as the tribal kingdoms of the far interior began to decline and desiccate. Patronizing great philosophers and artists, the Mauri Kings also took to the increasing trend of monasticism, founding many new desert monasteries.
Isemrases II, King of Africa and Mauritania (r. 552-574) ruled a semi-feudal patchwork of tribal cities. Much of his reign was preoccupied with maintaining this status quo while also attempting to expand the paltry fleet at his command. Over his reign he would deal with six separate rebellions, the most famous of them seeing Tingis sacked. In the final of these rebellions, in 566, many tribes of the Gaetuli were enslaved and annihilated en masse for their role in assisting the rebels, finally establishing the dominance of the settled, Latin speaking coastal tribes.
Famously, Isemrases patronized the great artist Maisara, whose work began a revival of Roman art and architecture in the region, characterized by a unique Berber flair. Romano-African merchant ships could be seen in all the ports of the Mediterranean, and the city of Lilybaeum, despite nominal Roman rule, enjoyed a great resurgence as Berber traders set up shop. Sicily as a whole benefitted enormously from this Mauri "renaissance", and the Prefect of Sicily, a Greek by the name of Maurice enjoyed a close relationship with Isemrases, viewing the Africans as a counterweight to the Goths.
The Goths under Athalaric, the arrogant son of Eutharic, was enormously popular with his nobles because he lived as they lived, drank as they drank, and ultimately, died as they died, drinking himself to death six years after taking the crown in 548. By contrast, his father Eutharic's long life had been a distinguished one. But despite having beaten back the Romans to a mere toehold in Italy and fought long and hard against the Franks, he nevertheless ruled an increasingly divided state, his Goths forming a military aristocracy which, after the depopulation of Italy from war and plague, was totally entrenched, and slowly becoming Romanized.
Concurrently, the work of Cassiodorus helped bridge the divide between Roman and Goth, while also promoting a resurgence of classical thought. One of the notable philosophers of the period, his work would ultimately have a long-lasting impact. Founder of schools and monasteries, it was not until the short reign of Athalaric that he achieved high office, and shortly after Athalaric's death he disappears from the historical record into a quiet life of contemplation.
Edit: I just wanted to promise this is not becoming an Eftal-wank.