Tarris

Tarris is the name of the mankind's home world, a large, rocky planet orbiting a pair of binary stars, the Golden Sun and the Red Sun. In the distant past, dozens of millennia ago, the planet was inhabited by members of the Katarru species or Elves, an ancient race of humanoid beings from a distant, forgotten world who spread their power across several planetary systems by means now forgotten.

While heliocentric models have already been established in many cultures and civilizations, even by those lacking the necessary scientific and mathematical knowledge to describe it rationally, Tarris is considered to be very close to the center of the universe, which is said to be between the two Suns. In most cultures of eastern Aviir, the Suns represent the beating heart of Kriulith (Red Sun) and the dreaming mind of Taari (Golden Sun), and therefore the origin point of creation. While this is not true physically, the Suns, especially the Red Sun, do have essential metaphysical and supernatural properties that have a strong influence on the nature of Tarris and the other planets it shares the system with.

Astronomy
Tarris is a terrestrial planet that orbits a pair of two Suns (a so-called circumbinary planet), and is the third-closest planet to them. Its orbit is nearly circular and located at a distance that allows Tarris to have a cool, yet moderate climate that is stable, although the presence of two stars causes some noticable variations due to the varying distance to either Sun. This can result in unpredictable weather pattern. Furthermore, the Red Sun experiences frequent eruptions and outbursts that can further affect the planet's climate. The most violent of these outbursts, which occur every few centuries or millennia, are so extreme that they can disrupt the conditions on the planet over long periods, and are often considerered omens of impending catastrophes that affect the whole planet, and very likely not of natural origin.

The Planet Tarris
Tarris has a diameter of over 15000 km, resulting in a circumference of 49000 km along its equator. The spherical nature of Tarris is already known to a multitude of cultures, and scholars have been measuring the dimensions of their homeworld for thousands of years with varying accuracy, and it can be assumed that cultures of previous Cycles did the same.

Tarris is volcanically active and rich in minerals, with several chains of volcanoes found in many zones across the planet's surface.

Tarris has a slightly tilted axis that results in seasonal variations.

The planet is orbited by three moons, although only one of them is sufficiently large, with the other two being little more than big asteroids. Furthermore, the planet is surrounded by a system of faint rings, likely the result of a former moon having been destroyed by unknown means.

Cosmology
The solar system of the two Suns is home to a total of eight planets including Tarris, five of which are visible to humans without the aid of visual instruments, and thus also known by cultures that have not yet developed telescopes. It is possible that there are more planets in this system at higher distances that simply have not been discovered yet as they are too dim. The outer three of these planets appear to be significantly larger than Tarris and the other inner planets, and do not show expected features indicating a rocky surface, instead showing bands of clouds and spiraling, colorful spots, which astronomers refer to as "eyes" and are thought to be giant storms. These giant planets tend to have rings much more prominent than Tarris, and seem to be orbitted by hordes of moons. The outermost of the rocky planets has a very dark surface or cloud cover, and therefore requires a telescope to be seen.

The skies above Tarris are covered in stars and other structures, such as colorful nebulae and a luminous band which many cultures refer to as a river, a road, a bridge or an abyss, and associate with Gods or other supernatural entitites or events. Observations with telescopes reveal that this band consists of countless, seemingly fainter and thus more distant stars, indicating that the system of Tarris and all the other stars visible are embedded within a larger structure consisting of inconveicably massive numbers of stars. This has caused paradigm shifts and distress among many cultures, who saw their worldview of Tarris and the Suns as being the heart of creation threatened; the views of individual scholars, astronomers and philosophers on this matter differ.

Distant past
Nothing is known about the planet's distant history before the arrival of the Katarru, and even from that era, knowledge is sparse. Extremely ancient Katarru documents, which are gathered and examined by scholars with arcane knowledge, indicate that Tarris was already populated before their arrival, and that they somehow changed to planet further. It is not known if humans originated on Tarris or another planet, or if they directly descend from the Katarru or were created by them. Most of Tarris' inhabitants, including scholars, believe that Tarris has always been mankind's home, and that the Katarru were divine beings from an earlier aeon or Elves, instead of a technological civilization, or don't even know of their existence at all. Their real nature cannot be known, but it certainly evolved something beyond mundane technology.

At one point in the distant past, the planet was subjected to cataclysmic events caused by extremely strange events, marking the disappearance of the Katarru. Since then, different civilizations have arisen and fallen, and new civilizations have risen from the ashes. These eras of decline often come along with immense catastrophes, and mark the edges of the Cycles. The previous Cycle, for example, was ended by a long ice age that froze over most regions on Tarris save for the tropical and subtropical zones, which also cooled down significanty however. While natural catastrophes like ice ages, volcanic eruptions and enormous floods cause mark the end of each cycle, there are many inexplicable, supernatural phenomena associated with them as well, indicating that they might be caused by some sort of divine, eldritch being mentioned in apocryphal scripts, called Astral Gods.

The Auniiri, or Dreamstriders, are individuals who can observe past events in dreamlike states through the eyes of individuals present at said events, and thus give further insights into the past. However, the further back they look, the blurrier and "dreamier" their sight becomes, blending with their own subconscious thoughts and expectations, and nobody so far managed to gaze back into the era of the Katarru, as something prevents them from even trying it.

Previous Cycles
Not much is known about the civilizations living in previous cycles, nor is it known how long they lasted and how many there have been at all. Some Auniiri have managed to get a glimpse of some of these ancient cultures, describing most of them as very similar to present cultures, while others are completely alien. Some ruins, so old that they resemble bizarre rock formations more than former works of architecture, are believed to have belonged to these cultures, although many are not even aware of the cycles and therefore believe them to be simply very old buildings.

As some cultures, usually the more tribal and "primitive" ones, survive the catastrophes at the end of Cycles, they might bring some knowledge of previous Cycles with them, and as they develop into high cultures, their knowledge can influence new cultures as well, albeit in changed form.

From the previous Cycle, three cultures are known in the east of Aviir:


 * The Men of Arnith, named so after the region were their ruins are found, whose lands stretched from the eastern portion of the Green Sea, the Emerald Gulf to the Crescent Kap in the south and the southern Bimarric Mountains in the north. They were known for their highly advanced metallurgy, working with unknown alloys that surpassed steel in resilience and hardness, as well as their naval prowess. It is said that their bloodline still lives on in the current population of this region, like the Sytholians, as well as ancient empires like the Ylurian Empire. It is unknown what they used to call themselves.
 * The Tralak Civilization, also known as Boreal Pyramid Culture, used to live along the northeast coast of Aviir, from Astarikaz in the south to the Pearl Sea and possibly even beyond in the north especially along the Tralk Mountains, after which they were named, but their remnants can be found as far west as the Bimarric Mountains. They have left behind monolithic architectural structures, especially very large pyramids, and were said to have created welded, black-white steel from the iron of meteorites found around the large Crater Lake. With the onset of the ice age at the end of the Cycle, they were driven south by the ongoing glaciation, as their numbers were sharply declining. Eventually, they seemingly merged together with the Men of Arnith. The Talethis are said to be the closest extant relatives of them.
 * The Tiremians who lived in the deserts and grasslands of the Kalsari Subcontient. Like the Tralak, they left behind large monolithic structures, but nearly nothing else is known about them.

Furthermore, another culture by the name of Q'Däthr is mentioned in several ancient documents, but it is not known were and when it was situated, only that it has apparently been the most advanced and richest civilization on Tarris since the disappearance of the Katarru.

Current Cycle
The former Arnithian people began to form city states a few millennia after the fall of their precursors, roughly 10000 BKF during the late stages of the ice age when the climate warmed up again, making them the first known civilization in the current cycle. They are said to be the most direct ancestors of the ancient Men of Arnith, although mixed with several Skreloid steppe tribes and Tralak peoples. The smithing techniques of their ancestors were forgotten, and they used bronze. These Arnithian city states were assimilated by the expanding Ylurian Empire at around 7000 BKF.

The ancestors of the later Xiahar race appeared at roughly 6000 BKF in the western mountain ranges south of the Sea of Shells. They began establishing a high culture shortly after their arrival, and were presumably the first known culture of this Cycle that primarily used iron instead of bronze.

Creation myths
There are hundreds of different creation myths that are often radically different to each other, but many share one common trait: that reality is merely a dream of an higher entity.

In Taarism, the prevelant belief system in much of the easternmost part of Aviir, the world is the dream of the god Taari, represented by the Golden Sun. In ancient times, Taari dreamt of another world, represented by the pre-cataclysmic era of the Elves. The god Kriulith, Taari's brother, was jealous of his splendrous creation, and therefore awoke Taari and destroyed his world, leading to the Kataklysmos. Enraged, Taari challenged Kriulith to a swordfight, which lasted for countless days and nights without a winner emerging. Yet in one moment, Taari managed to strike down Kriulith. He cut open his chest and tore the still beating heart out of his body, and threw it across the murky waters of the primordial ocean, intending to lay down and sleep again where it would land. He eventually found it and dreamt up a new world, which is current reality, with Kriulith's heart represented by the Red Sun. As Gods cannot truly die, for they have never been alive in the same way mortals are, Kriulith is now doomed to search for his heart, unable to dream and create on his own. Instead, he must rely on reaching mortals within Taari's dream to do his will and return to him the gift of dreaming a world.