"It is a time of saviors. The west has Jesus and the east has Mazdak."
Zoroastrian priest Kavad Yasmin comments on the beginning of the Forth Great Caucasian War of 1076.
In late 6th century AD, the Sassanian and Roman Empires had both begun to crumble. Hanging on to ancient institutions in a time long past their expiry, change was coming and the world knew it.
Amongst the two, the latter had grown far more unstable than its Greek counterpart. it's armies were poorly led, her nobility unruly and the Sassanian themselves a shadow compared to the great Khosrau Anushirvan. As the populace grew rebellious, the Sassanid Empire was plagued by heresies and heathens, most prominent of which being the Mazdakites and Nestorians. The Armernian War and the Third Iberian War saw costly, ultimately pointless stalemates. Again and again, Persia seemed just that little bit from ransacking Constantinople and restoring the glory of Cyrus, but they were pushed back twice from the gates of Anatolia.
In 600, powerful Abrahamic Arab warlord-preacher Muhammad would unite the Arabs under the Confederation of the Rashidun (trans. Rightly guided ones), aided by his lieutenants Ali and Omar. Muhammad, sensing opportunity would send his best general, Al-Walid into Eranshar, ordering him to make way for Ctesiphon. At the battle of Seleucia, Al-Walid broke through the desperate defence of the Persian kataphraks, at which he pushed into Ctesiphon in the cumulation of the conflict.
As Muhammad ordered Al-Walid to return, the general's ambition would not let him stop. Eranshar fell to the Rashidun Arab hosts in 10 years, with resistance continuing in the countryside. In this time, Al-Walid began to see the paganism Muhammad taught as a burden. His solution was to embrace the teachings of the locals. What started as celebrations of Norwuz or a new importance placed on fire soon became a strange Arab interpretation on the teachings of Ahuramazda. Under Al-Walid, the teachings of Mazdak were too embraced, serving well to convert the populace to Arabic Zoroastrianism. Focusing on the profileration of "justice" and "equality", the Sulaymanid Dynasty quickly won the hearts of the populace. Al-Walid would tear down the families that had dominated the Persian state for so long, enforcing the new centralized state.
A new wave of Arab-Persian and Persian-Roman wars began. With the Sulaymanid Dynasty beseiged on all sides, Al-Walid proved his diplomatic prowess by setting the Arabs and Christians against each other with the revolt of the Lakhamids and the Jewish War. By the mid 800s, the Sulaymanids had become as Persian as Persian could get, albeit with an uncanny focus on military might. They had prospered by exploring the Arab-Persian conflicts to instead gain the upper hand in the great game of the Levant--even spreading the just teachings of Mazdak to Cathay and Shindustan. It had however provoked the forces of the West, inviting a series of century long religious wars. With the short interruption that was the Arabs passing at last, the eternal conflict between Ctesiphon and Constantinople grinds on, with no victor in site.
"Had Liu Bang not wept as he stood on the banks on the Yangtze? Do I now not weep in the peaks where the Fire God dwells?"
