Nestled deep within the Unknown Regions exists a world of captivating mystery and natural beauty, known as Csilla. This planet, adorned with a captivating frosty veil, is the home of an enigmatic species known as the Chiss, who have survived on the frozen tundras for many millennia. These blue-skinned and red-eyed humanoids originated on a world that was once dominated by temperate forests, where lush greenery swayed in the embrace of temperate winds, and ocean blue glistened in the light of its primary. However, the passage of time brought about a dramatic shift, plunging Csilla into the icy embrace of a perpetual winter. The very climate of the planet was transformed in the unforgiving grasp of a global ice age, with snow-capped panoramas and frozen vistas dominating the planetary landscape. Only a few sanctuaries of verdancy remain, where trees adorned with delicate ice crystals that glisten in the pale light of this world's sun endure, and give shelter to the native flora and fauna that still prevail in the face of endless winter.

Csilla is a rocky planet that is slightly smaller than average when compared to other celestial orbs of its class. Several notable landmarks make up the planetary surface of this icy world, with one of the most famous being four colossal volcanoes known as the Four Sentinels. These ancient fire-spewing behemoths, believed to be as old as Csilla itself, are both natural wonders and symbols of the planet's enduring spirit. Each of them bears a name: the Crystalline Spire, the Frozen Colossus, the Glacial Monarch, and the Diamond Titan. They stand as silent sentinels, guarding the planet's secrets and providing breathtaking vistas for intrepid travelers. Another renowned landmark located on Csilla are two massive caves, known as the Crystal Grottos and the Frostfire Abyss respectively, which delve deep into the planet's icy heart. The Crystal Grottos are a mesmerizing wonderland of translucent formations, while the Frostfire Abyss is a place of stark contrast - a cavernous expanse where subterranean fires burn, providing much-needed warmth in Csilla's freezing depths.

When viewed from orbit, the frigid homeworld of the Chiss appears to be largely uninhabited. However, nothing could be further from the truth, as these brilliant humanoids have skillfully integrated their architecture into the existing landscape. Their cities are often built beneath the planet's surface, or underneath the vast glaciers that dominate Csilla’s landscape, a testament to the covert and enigmatic nature of its natives. In fact, the planet very much resembles an ecumenopolis, with most of the subterranean terrain consisting of vast urban conglomerations harbouring billions of Chiss, who are the lifeblood of the planet. Metropolises like the planetary capital of Csaplar, or Ac'siel - the largest subglacial city on the planet - are marvels of engineering and infrastructural planning, providing shelter, warmth, and security to its many blue-skinned citizens.

The history of Csilla and the Chiss is the history of the ruling families and the various incarnations of the Chiss Ascendancy. Ever since the planet plunged into an ice age roughly five millennia ago, the Ascendancy has been the guardian and protector of its citizens, made up and governed by various families that had transcended beyond the traditional familial ties of blood and relation, and developed a meritocratic system of adoption. Over the course of Chiss history, these families have vied for political control and influence over the Ascendancy, with the greatest honour and prestige a family could attain was becoming one of the Ruling Families. As a result, Csilla and the Chiss have gone through many changes and dynamic societal movements, with one incarnation of the Ascendancy choosing to ally itself with the ancient Sith Empire and then retreating into isolation, while the most modern incarnation has chosen for an alliance with the Galactic Empire. Despite this, the Chiss remain a people focused primarily inwardly, striving to attain a state of perfection within themselves, as well as within their society.