World Si Vis Pacem, Para Bellum [Worldbuilding & Planning]

[Eunoia]

Setting the Scene

The story takes place in 370 CE, during the long period of conflict between the Roman Empire and the Sasanian (Sassanid) Persian Empire, two ancient superpowers locked in centuries of intermittent warfare, political rivalry, uneasy diplomacy, and cultural exchange. Rome and Persia are both highly advanced imperial societies with long histories, elaborate court traditions, professional armies, rigid social hierarchies, and strong ideas about legitimacy and rulership. They hate each other, imitate each other, trade with each other, and remain deeply obsessed with one another.

The border between them stretches across Mesopotamia, Armenia, Syria, and the eastern frontier provinces; regions that have spent generations changing hands, rebuilding after wars, and surviving beneath the weight of imperial ambition.





The Roman Empire

Rome is vast, old, bureaucratic, and deeply hierarchical. Even weakened by internal instability and endless wars, it still views itself as the center of civilization. Roman identity is tied heavily to ideas of order, law, military discipline, and imperial superiority. By 370 CE, the empire is increasingly centered around Constantinople in the east, though Rome itself still carries enormous symbolic weight as the old imperial heart of the empire.

Roman politics are volatile. Court life is full of rival noble families, military influence, assassinations, succession crises, religious disputes and fragile alliances. Public image matters enormously. Emperors and rulers are expected to project strength constantly, even when the empire itself is strained.

Roman society is deeply patriarchal. Women can wield influence, particularly within the imperial court, but often indirectly or through dynastic legitimacy rather than open authority. A ruling woman would face enormous scrutiny, especially if there are male heirs or rival claimants nearby.



Roman Military Culture

The Roman military remains one of the empire’s defining institutions. Though the classical legionary image still influences Roman identity, the military of this period is more diverse and adaptive than the early empire. Cavalry plays a far larger role than in earlier centuries, partly due to Persian influence. Roman armies include heavy infantry, cavalry, archers, mercenaries, frontier troops and allied forces from various provinces.

Military service is tied heavily to prestige, political power, and citizenship.

The Roman frontier with Persia is one of the most militarized regions in the known world.



Roman Religion

By 370 CE, Christianity has become deeply embedded within imperial Roman society, particularly among political institutions and the upper classes. However, older Roman beliefs and local pagan traditions have not disappeared entirely. Temples, older customs, and regional cults still survive in parts of the empire, creating ongoing religious tension beneath the surface of public life. Religion within Rome is political as much as spiritual. Disputes over doctrine, legitimacy, and divine authority can influence entire wars.





Persia
The Sasanian Empire

The Sasanian Empire is Rome’s great eastern rival. Ruled by the House of Sasan, the empire presents itself not merely as another kingdom, but as the rightful continuation of ancient Persian imperial tradition. Persian kings use the title Shahanshah (King of Kings). Kingship is treated as sacred, cosmic, and divinely sanctioned.

Ctesiphon is the primary imperial capital of the Sasanian Empire. Located near the Tigris River in Mesopotamia, it functions as the political and ceremonial center of Persian imperial life. For Rome, Ctesiphon represents the heart of Persia itself.

Persian court culture is elaborate, ceremonial, and intensely hierarchical. The empire values nobility, military prestige, lineage, diplomacy, court etiquette, and public displays of wealth and authority. Unlike the Roman image of controlled austerity, Persian aristocratic culture tends toward visible magnificence; richly embroidered silks, gold jewelry, perfumes and incense, bright and colourful fabrics, ceremonial armor, and lavish feasts.

Persian nobility are expected to be both politically educated and militarily capable.



Persian Military Culture

Persian warfare places enormous emphasis on cavalry. The elite mounted warrior aristocracy are known as the Aswaran, noble cavalrymen trained from youth.

Heavy cavalry and cataphracts are especially important. Cataphracts are heavily armored horsemen, sometimes with armor covering both rider and horse, designed for devastating shock charges.

Persian princes are expected to participate in military campaigns from a young age. Royal legitimacy is tied closely to visible courage and battlefield competence. A prince who has never ridden with armies would likely be viewed as weak.



Persian Religion

The dominant religion of the Sasanian Empire is Zoroastrianism. The supreme deity is Ahura Mazda, associated with wisdom, truth, order, and light. The religion centers heavily around the struggle between truth and lies, order and chaos, and light and darkness. Fire is sacred within the religion, not because Persians worship fire itself, but because fire represents purity and divine truth.

Royal authority is closely tied to the concept of divine glory, often referred to as xwarrah (a kind of sacred royal radiance or divine favour associated with kingship).

Sunlight, gold, and radiance all carry strong symbolic importance within Persian royal imagery.





Greece & Hellenistic Influence

Though Greece no longer exists as an independent imperial rival to Rome in this period, Greek culture remains enormously influential throughout the eastern Mediterranean. Greek language, philosophy, education, rhetoric, and art shape much of elite society across both Roman and eastern territories.

Many educated nobles (Roman and Persian alike) would likely speak Greek to some degree. Greek remains one of the major languages of diplomacy, scholarship, and administration in many eastern regions.

Because of Alexander the Great’s earlier conquests centuries prior, Persian and Greek cultural influences have already been entangled for generations.





Court Culture
Roman Court

Roman court life is tense, competitive, and deeply performative. Reputation matters, and people survive through political alliances, marriage, military favour, strategic loyalty and a careful;y curated public image. Rumours can destroy lives as effectively as armies.

Foreigners within the court are viewed with fascination and suspicion simultaneously.



Persian Court

Persian court culture is more overtly ceremonial and aristocratic. Hierarchy is rigid and carefully observed. Appearance matters enormously; clothing, posture, jewelry, language, and etiquette all communicate status.

Persian nobility are expected to embody visible refinement alongside military competence.





War

Neither Rome nor Persia is truly winning. After centuries of warfare, both empires are strained economically, politically, and socially.

Entire generations have grown up knowing little except border conflict.


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[Eunoia]

Name:
Darius, Shahzadeh of the House of Sasan

Alias(es):
Dārayavauš (DAH-rah-yah-VAO-oosh), The Lion of Ctesiphon, The Red Prince

Age:
24

Gender:
Male

Occupation(s):
Shahzadeh of the House of Sasan and commander of the Aswaran (an elite cavalry corps)





Description:

Spoiler: Darius

Darius’s nose sits slightly crooked from a break that healed imperfectly years ago, while a small notch through one eyebrow hints at a blade that once came far too close. Thick black curls frame a face marked by a jagged scar stretching from his cheekbone to beneath his jaw, the old wound pulling faintly whenever he smiles. Beneath heavy dark lashes rest striking honey-gold eyes, lined with kohl, deceptively warm at first glance. The prince’s complexion bears a sun-warmed olive tone; his body is lean, toned, and muscular after years of warfare and cavalry training, while his hands are rough with calluses and old cuts scattered across his knuckles. Faint smile lines linger around his mouth, subtle traces of someone who laughs more frequently than his reputation might suggest.

Height:
6'1

Wardrobe:

Spoiler: Clothes

Darius favours rich, extravagant clothing, gravitating almost exclusively toward shades of deep red silk embroidered with gold thread. His wardrobe reflects both noble excess and military prestige: layered robes, fitted tunics, long ornate coats, broad belts adorned with precious metals, and finely crafted jewellery. Despite the luxury of his appearance, there is still some semblance of practicality. Soft silks are often paired with sturdy leather riding boots and garments cut for ease of movement. The scent of incense, smoke, and spiced oils tends to cling to both his clothing and skin. His armour carries the same philosophy. Rather than plain steel, Darius favours ornate gilded scale armour draped with crimson fabrics and gold detailing, crafted as much to inspire awe as to protect. His most distinctive piece is his helmet: forged in the likeness of a lion, with sculpted features framing the face and a mane-like crest sweeping back along the crown. Upon horseback, clad in red and gold beneath the snarling visage of the lion helm, he appears less like a man and more like something pulled from imperial legend.





Personality:
Darius moves through the world with the kind of confidence that borders on arrogance. Social by nature, he gravitates toward crowded halls, conversation, spectacle, and excess, possessing a charisma that makes him difficult to dismiss even for those who dislike him. He enjoys luxury openly and without shame, and there is very little restraint in the way he presents himself to the world. At first glance, he can seem shallow because of it. Vain, indulgent, a prince more interested in appearances than substance. In reality, much of that image is intentional. Darius is deeply aware of how he is perceived and has long since learned to weaponise charm and humour. Though quick-tempered and often sharp-tongued, there is a warmth to Darius that emerges more clearly among those he trusts. He laughs easily, grows attached too quickly for his own good, and loves with a loyalty so stubborn it can become self-destructive once given. Years of warfare and political expectation have hardened him, though not enough to make him cold. If anything, Darius feels things too deeply and too intensely, burying them all beneath pride and performance.





Skills:
Trained in swordsmanship, spear combat, and horseback fighting from a young age.
Charismatic speaker.
Highly educated in matters of court politics, diplomacy, and imperial etiquette.
Fluent in Middle Persian and Greek, with at least conversational Latin from years spent around Roman officials and diplomats.
Experienced strategist with strong battlefield instincts and a practical understanding of military logistics.
Exceptional horseman.
Socially adept and highly observant, particularly skilled at reading people.
Trained in hunting, falconry, and other noble pursuits expected of Persian royalty.





Backstory:
Born into the House of Sasan, Dārayavauš was raised within the heart of the Sasanian court alongside his three brothers and younger sister, surrounded from birth by the expectations that seemed to follow royal children long before they were old enough to understand them. Life within the royal household was rarely simple. Affection and rivalry existed side by side, and while Darius was never the most disciplined of his siblings, he possessed the sort of charisma that naturally drew attention to him, whether welcome or not.

Like many princes of his station, he was educated not only in matters of politics and diplomacy but also in warfare. By the time he reached adulthood, Darius had already earned a reputation for himself among the Aswaran cavalry.

Though born into luxury, Darius was never kept far from war for very long. He rode with soldiers while still young enough to find glory in it all, and those early years shaped him more than anything else. The victories came quickly, as did the praise, and Darius grew used to being admired for it. Somewhere along the way, that confidence hardened into arrogance, fed by the belief, encouraged since childhood, that he had been born for greatness.

However, that belief fractured during a disastrous campaign against Roman forces near the western frontier. By the final hours, the battle had dissolved into chaos; cavalry lines broken apart, siege equipment burning, horses screaming beneath the crush of bodies as formations collapsed under panic. Darius fought until retreat was no longer possible, refusing to abandon his men even after the battle had already been lost. He was eventually captured alongside what remained of them, bloodied and exhausted.

His imprisonment should have ended with ransom negotiations or political exchange, as befitted a prince of his station. Instead, Rome chose humiliation. Stripped publicly of both rank and identity, Darius was transported west not as a diplomat or hostage, but as a spectacle. A conquered eastern prince displayed through Roman streets before eventually being sold into gladiatorial combat, valued less as a man than as the novelty of watching Persian nobility bleed within the arena.


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