Thalissian Empire

The Thalissian Empire was an empire spanning much of the southern Helerin Archipelago. It lasted for approximately 600 years and was based around the city of Thalis on Mar Mabon.

For centuries, the Thalissian Empire was the dominant power of the Helerin Archipelago, rising from a single city to an empire that controlled vast swathes of territory. Its legacy of grandeur, ambition, and inevitable collapse continues to shape the political and cultural landscape of Helerin today.

History

The Empire emerged in the wake of the Tekkaron catastrophe of 530, as Mar Mabon and its neighbouring islands reeled from chaos. The young king of Thalis, Varlonn Arteris, defeated Jalus III of Forbin at the Battle of the Thalis Plains in 670. Having secured vast territory across both Mar Mabon and Mar Miskun and defeated his primary rival, Varlonn proclaimed himself Emperor.
During its height, from the 8th to the early 10th century, Thalis controlled not only Mar Mabon but also Mar Miskun and much of Teros Minor. Its fleets dominated the Sea of Fair Winds, the Hayil Strait, and the Straits of Charthol, enforcing a trade monopoly that brought staggering wealth. The empire’s capital was a hub of culture, bureaucracy, and architectural splendour, renowned for its towering citadels, grand temples, and an extensive network of aqueducts.
Yet this golden age could not last. By the 10th century, the Thalissian Empire was buckling under its own weight. Corruption riddled its bureaucracy, distant provinces like Mar Miskun and Teros Minor grew increasingly independent, and external pressures from the Realm of Forbin and Remon, and rival city-states threatened trade and security. The eruption of Mount Thanak in 1178 further devastated the empire’s agricultural base.
The end came in 1197 when a coalition of forces from Teros and Forbin besieged and sacked Thalis itself. The fall of the imperial capital marked the collapse of the empire. In the aftermath, successor states and city-states, such as the League of Mar Miskun and the Mar Mabon Townships, rose to fill the vacuum.
The ruins of Thalis and its once-great cities stand as grim reminders of the dangers of overextension, ambition, and hubris.
See also: History of the Thalissian Empire

Geography

The core of the Thalissian Empire lay on Mar Mabon, a vast and rugged island dominated by the Burning Peaks mountain range, the desolate Curmon Desert and Gathoran Sands, the arid Jarocan Plain, and the more fertile Thalis Plains. The empire's heartland was the Thalgas River valley, where the city of Thalis rose near the river’s source.
Beyond Mar Mabon, the empire extended its reach to Mar Miskun, a smaller island to the west separated by the Straits of Charthol. The fertile Riverlands in the west, and ports such as Penstrarn and Ashanok were vital economic hubs, securing the empire's hold over maritime trade.
During its peak, the Thalissian Empire’s sphere of influence also stretched into Teros Minor, particularly the strategic port city of Elinann. This expansion provided a staging ground for projecting military power into Teros Major though this hold was short-lived.
Today, Mar Mabon’s geography remains a mixture of desolation and fertility. The plains, mountains, and river valleys of the north and east are dotted with ruins of Thalissian fortresses and settlements. These lands are now home to nomadic tribes and wild reatures.

Major Settlements

The cities of the Thalissian Empire once represented its might and culture. Many are now ruins or have evolved into independent townships and realms.

Thalis

The empire’s capital, situated on the Thalgas River, now a ruin of overgrown citadels and collapsed aqueducts. Its grandeur lingers in stories and shattered stone, but its streets are silent.

Tirmallan

Once a key city on the Thalis Plains, now abandoned and crumbling, home to scavengers and shadowed by local legends of haunted vaults.

Morskaddin

Located in the Shidar Highlands along the Morskad River, this town fell into ruin during the empire’s decline, though scattered survivors and wanderers still pass through.

Penstrarn

and Ashanok: Formerly Thalissian strongholds on Mar Miskun, both cities were sacked during the collapse. Ashanok has recovered as part of the Mar Miskun League, while Penstrarn remains a shell of its former self.

Ashanok

Orbont

Argonsa

Elinann

The empire’s hold on Teros Minor centred on this port city, which was lost to rebellion and now stands independent.

Gathansin

Several other cities and fortresses, including Minarthann, Shidoram, and smaller settlements along the rivers and coasts, have fallen into ruin or been subsumed into emerging powers.

Power and politics

Governance

The Thalissian Empire was an autocratic monarchy, with the emperor wielding absolute authority over law, military, and administration. Succession followed the dynasties of House Maraden, House Arteris, House Verradon, and finally House Lorrellan. At its peak, a complex bureaucracy managed taxes, trade, justice, and military affairs, but in practice, corruption and factionalism were rife.
Provincial governors, known as Stratarchs, often operated as semi-independent lords, particularly in distant regions like Mar Miskun and Teros Minor. In times of weakness, their ambitions undermined the central authority, hastening the empire’s fragmentation.

Military

The Thalissian military was the backbone of its power, boasting a formidable navy and a disciplined standing army. Its fleets controlled vital maritime routes, while its legions enforced the emperor’s will across the archipelago.
However, by the 10th century, the empire’s forces were overstretched and underfunded. Rebellions in Mar Miskun, defeats in Teros Minor, and a lack of reinforcements contributed to the empire’s decline. By the time of the final siege of Thalis, the military was fragmented and demoralised.

Other powers

Economy and culture

Thalissian culture left a deep mark on the archipelago. Its legal codes, administrative structures, and monumental architecture influenced successor realms. Temples to gods such as Frenar, libraries filled with Thalissian texts, and grand plazas became symbols of power and learning.
Thalis was a melting pot of ideas, drawing scholars, artisans, and merchants from across Helerin. The empire’s art, music, and literature were widely admired, blending practicality with ornate flourish. Even after the fall, traces of Thalissian culture persist in the customs, architecture, and law codes of Mar Mabon, Mar Miskun, and beyond.

Legacy

Though the Thalissian Empire has long since fallen, its shadow lingers. The Mar Mabon Townships and the League of Mar Miskun are direct heirs to its former territories, shaped by its legacy yet determined to avoid its fate. The ruins of Thalis, Tirmallan, and other cities continue to draw treasure hunters and scholars alike, eager to unearth lost secrets.
For many across Helerin, the Thalissian Empire is a cautionary tale of ambition undone by greed, of glory consumed by overreach, and of a people brought low by their own excesses.

Type

Geopolitical, Empire