The Boralissian Empire was created in 6,666 BCE after the civil war against the Psion imperium , they were Aegiuns who had been used as slaves, with support of 27 other allies they defeated the Psions and the psion imperium left the sector.
The Boralissian Empire at it's height controlled 2900 worlds from Wubellia to Omnipolus, with numerous races under there control.
Terrans often equate it to the galaxy's equivalent of the "Roman Empire"
The Imperial Civil War
In the 6,700's BCE the Psion Imperium had over-extended it's armies by fighting wars against the Kandlian Empire (led by Swarm King: Daesynth II) the wars of conquest against the distant Kuxeri Imperial Collective and finally the regional player, Hessenyan Empire. the Aegiun slaves led by Salkaspid saw an opening and launched a raid on an Aegiun armory in Yellaws Valley, taking control over a cache of weapons and vehicles bringing destruction to the destruction of the city of Tyrienance and eventually broadcasting their victory across the stars, the Psion Imperium hadn't even sent forces until seeing the signal and by then it was too late, the broadcast rallied slaves and oppressed citizens on, Kuparia, Kyleria, Copatira, Tyrin, Polotani and Wubellia.
Battle of Kippidea
Long before the Viserak advanced past swords and shields, the new rebellion had taken control of large portions of the worlds they rebelled on, the Psion Imperium decided to use a super weapon, a weapon known as the "Star Breaker" along with a large fleet they advanced the StarBreaker and the fleet to planet Li'Jasima and ended up glassing the planet exterminating all life on the surface, killing a massive army of rebels, but ralying them even further, A rebel fleet led by Orelachen: Landoylyte attacked the much larger StarBreaker fleet, destroying it killing 500 Imperium officers.
The Imperium's leader Arclek: Aldari Guan continued the war against the rebellion
Battle of Chrysalvio (6,674 BCE)
The Imperium discovered the Rebel base on Chrysavlio, the Imperium sent a massive army led by Orelachen: Dandeross with his invention the Psion Combat Walkers, which laid waste to the Chryalvian base only two rebel ships escaped, the war would drag on for a few more years.
Battle over Adairis (6,669 BCE)
A tribal world was the next stop for a major conflict, the Psion Imperium landed on planet Adairis to subjugate the population known as the "Viserak" or in Ty'Ger language "Xualwhu" the tribal forces were exterminated on the small continent of modern day "Sarkosphere" the rebels landed on this world as well and allied with the local Xualwhu population with the Xualwhu charging first the rebels cut off the Imperium's power supply, cutting off their connection to their space station in orbit of Adairis, while the Space Station was distracted, the rebels led by LanSalkaspido (son of Salkaspid) attacked the space station by surprise, the station was destroyed and descended into orbit of the planet, soon it crashed into the Kynorhyncha ocean and laid undiscovered until 1995 when the Viserak had become powerful.
The battle was won, but most of the Xualwhu who assisted the rebels were killed, those who survived were educated and drafted into the rebel army never to see their homeland again, they would later be given a home on Demitros after the Rebels took it from the Imperium, Demitros would technically be the first Viserak Colony.
Eventually the rebellion would prove to difficult to quell as the rebels gained more and more and eventually forced the Imperium to retreat.
After nearly 2000 years of rule, the Boralissian fell in 4981 BCE by an alliance led by the De'Psi religion, the religion itself eventually waned in 4820 and a void in the power structure was left empty, this led to the "Age of Chaos" from which several Aegiun States fought against eachother and other sentient species for centuries. while none had any real power.
The First Kandlian Invasion in 1,000 years occured in 900 BCE where all of the opposing factions of the age were destroyed and assimilated, luckily the Praetorians were immune to the Kandlia (which dissapeared later on) eventually in 1816 CE the Wubellian Empire was the first stable superpower to rule for a significant time period, basing their policies on the ancient Boralissian Empire.
The Wubbelians, Wolfenzi, Demitros and even the Viserak based some of their policies and structure on those of the ancient Boralissians, even the UTSEA itself incorporated aspects of it into itself.