The Golden Elves of Leosi found their way to the island of the Shining Sun in the earliest days of the world, during the rise of the Gaatian Empire. While the historical records of the elves were not well maintained as they remained oral in passage for thousands of years, what little is known comes from documented accounts of Mosian invaders from the south as they waged war with the elves in the west. After the destruction of the elven cities of Azuli the scattered remnants of the civilization would be reborn across Eldor. Drifting far from their homes in the Forests of Azuli the elves would become distinct relatives of their wild brethren participating in selective reproductive practices and abandoning their once innate connection to the woods, instead of pouring their magic and hearts into the creation of their own nature: art, culture, drama, and wine. Named not only for their fair and sometimes metallic complexion the Golden Elves also have become known as one of the richest races on earth. The placement of Leosi has lead to years of trade and movement control between Xifang, Eldor, and the Homeland. This accompanying the unique fertile lands to the north of the straight has led to thousands of years of prosperity for the nation. 

Sometime during the Esoteric Age, the encampments and the scattered settlements of the island would condense into the northernmost of the city of the country still standing: Deu Riviér. This small settlement would become a bustling trade port in a manner of years although due to a lack of documents from the period it is unclear as to what lead to the increased traffic through the Leosian Straights. By the time of the 1st Modern Age the city was economically and culturally mature, leading to the planning and eventual construction of a new capital of the country on the coast of Lake Soliel. 

In the year 34, 1st Age, the grand city of Soliel was created. A well-planned and meticulously designed city, the elves of Leosi would commission the finest architects from Eldor and beyond to help design the city, utilizing years of elven artistic influence and training.

The current capital of the nation houses the Bronze Banks, one of the few Dwarf-Elf collaborative efforts seen in Illumire. These massive bank vaults created and managed by the Red Dwarves of the Rose Spine Mountains are some of the largest precious metal reserves in the world. The city of Deu Riviér is also host to Mint of Leosi, a dwarven run minting plant that became responsible for approximately 75% of all currently used coinage on the earth in the year 682. The reason for this monopoly on currency is not only the secured backing of the coinage but also the cataclysmic event of the fall of Mosian. This economic shock and political upheaval were wisely taken advantage of by the Leosian Mint, which offered, to many Kingdoms of the world, a balanced and controlled currency and a constant income for the royal and political powers. While many powers saw the transition as an advantageous temporary fix the Leosian government has kept a firm hold on their monopoly and use the economic power it governs to ensure their currency's stability and continued use.