The Dawn Ages
"The Dawn Ages" is the term used by modern Matoran scholars to describe the earliest days of the universe, now largely remembered as myth. This was the time in which the founding principles of the Matoran Universe were established.
History
Long ago, fearing the destruction of the planet of Spherus Magna, the Great Beings created the Great Spirit Robot as a machine capable of mending their planet. However, for complex reasons, they knew that the planet could not be reformed for several thousand years, and so they sent the Great Spirit Robot on a mission of space exploration in the meantime. The robot was governed by an AI known as Mata Nui, who was able to both study alien civilizations and exercise complete control over the environment within his new body.
The Great Spirit Robot, a machine the size of continents, needed a vast amount of labor to keep itself running. This was accomplished by the use of biomechanical beings known as Oropi, who would perform unique functions to assist in its maintenance and repair. The first prototypes of Oropi became ancient and powerful beings in the Matoran Universe, including beings such as Helryx, Artakha, Karzahni, Orde, Takua, and Tren Krom. In its initial stages, the Great Spirit Robot was built on the surface of Spherus Magna, at first by a combination of Agori labor and vast machines, and later by Oropi laborers. To later Matoran, this was known as the Time of Darkness.
Once the Great Spirit Robot launched into space and left Spherus Magna, it could no longer rely on resupply and external maintenance, so the burden of all maintenance fell on the Oropi. The most common species of Oropi by far are the Matoran, who were initially Unawakened, meaning that their intelligent minds lacked any sort of emotion or ego. This suited their design specifications as the perfect laborers. However, the rogue Great Being Eparchos, who had stowed away inside the Great Spirit Robot in the body of the Po-Matoran Velika, decided to Awaken the Matoran, unleashing a process which granted the diminuitive workers free will and emotions on par with every other being. This decision instituted a massive ethical quandary within the society of other Oropi, who split on the issue of whether it was ethical to force Matoran to work in conditions that they now found cruel or unsuitable.