Rosen: City of the Sun, Throne of Fire, Capitol of the Horizon Empire==Rosen: The City Beyond the Horizon. Rosen is a semi-mythical Imperial City beyond the Jadess Sea. It is the City of the Sun. It lies beyond the farthest western horizon upon the very rim of the realm of Aetherea. It is the crossroads of Aetherea and the Primordial Chasm . It is likely that Rosen has served as an transplanar crossing point for aeons. In the First Aeon of Aetherea, it is said, this is where the Valar disembarked from the Celestial Ship which once bore the Sun on its heavenly courses. This is where they began to take possession of creation. Legends also claim that Rosen was the beachead for the invasion by a Heavenly Host of celestials employed by the Valar to retake Aetherea from Morgoth after the First Darkness. The Celestial Ship was destroyed during this invasion (and its wreckage supposedly lies within the Temple of the Tempest in Rosen).
After the Elvenkind awoke on the primordial Shores of Twilight and responded to the Valar's invitation to seek out the Blessed Realm , the Quenar (The Elves that did not tarry) arrived at the Rim of the World after a long journey. On the Last Shores they found the Sun Charioteer, Helios and his footman Solaren resting upon the shores before moving beyond to recomense their journey. Because they Quenar had persevered so long, Helios had compassion on them and agreed to ferry them across the Primordial Chasm to the Blessed Realm. However, he could only take a small complement on each journey.
A faithful few Quenar pledged stay behind and dedicate themselves to Helios ' service, to tend his steeds, and repair his chariot in thanks for his assistance. Overtime this complment grew into a mighty city, as many Quenar decided to stay, rather than join the Valar in the Blessed Realm. Because Rosen was in the shadow of the Valar, it was greatly blessed. Over the course of many ages, Rosen became a kingdom a capital city of a great empire. The Empire came to be ruled by the guild of Sun Priests (Coachmen ) which served Helios.
Helios continued to be the protector of the city, even as the Horizon Empire recrossed the Jadess Sea against the wishes of the Valar and subdued many peoples and cities, because Coachmen, his guild of Sun Priests faithfully attended to him after his daily voyage.
Eventually, Horizon found out how to bridge part of the Primordial Chasm connecting Rosen with the celestial city of Union (which sits at the crux of transplanar highways). Horizon temporarily occupied the Union. When the Manwe , the King of the Valar heard that Union had paid tribute to Horizon, he sent a Heavenly Host to cleanse and reoccupy Union. He ordered Solaren (Helios' footman) to command it.
Horizon was pushed back, Union reoccupied, the Celestial Bridge destroyed. Helios, hurt by Rosen's betrayal, no longer rested at Rosen, however neither did he withdraw his protection. The Coachmen faithfully await his return.
Solaren removed the Coachmen from power and installed an emperor. He had celestial artisans specially craft a throne out of Sunfire. He installed a half-elf/celestial as an Emperess, then he and his army left for Union. This first emperess, Elveahendi Ayselos , established a mighty Ayeselian Dynasty .
Horizon turned its energies elsewhere, strengthening its position across the Jadess Sea under its new, powerful emperors. It became a great seafaring empire founding powerful trading cities across many islands and along the coast, ushering in a golden age of peace, prosperity, and trade. Eventually its control over its peripheries eroded, its emperors became embroiled in a series of destructive foreign and civil wars. And, the last Horizon ship departed across the Jadess. At this time, it is said that the City of the Sun had close to 1,000,000 inhabitants. This is the last thing known.
Horizon left a strong legacy in the places that used to call her mother. It left behind powerful cities and trade networks. It is also a popular prophecy that the Fire Throne (emperor) with return to reclaim what he has lost.