Rebellion
The first rebellion occurred in Imperial Year 1046, more than a thousand years after the reign of Nicholas I. A planet on the fringes of Imperial Space, Holcroft III, announced that it was seceding from the Imperium and blockaded its own jump gate to enforce the secession.
But an Imperial Fleet under the personal direction of Imperator Tyson II arrived and obliterated the blockading fleet, then proceeded with a punitive bombardment of the rebellious planet.
Unfortunately this brutal display of Imperial might had an effect opposite that intended and inspired future rebels to choose more strategic forms of insurgency. Before long the Imperial Fleet was spread thinly dealing with smaller brushfire revolts all through the Imperium, a task for which it was not ideally suited.
This led inevitably to the first defeats of Imperial Flotillas at the hands of rebel forces.
The Mad Imperator’s Fleet
By the time Mad Imperator Hugo ascended to the throne the situation had become desperate. But instead of reaching a compromise with the rebels Hugo redoubled his efforts to preserve the prerogatives of the Great Houses.
Although brilliant in his own way, Hugo was the product of centuries of inbreeding among the Great Houses, though the occasionally extreme behavior that would eventually earn him the title ‘Mad Imperator’ was overlooked because of his determination to preserve the Imperium intact.
In order to carry out this ambition, Hugo embarked on the greatest expansion of the Imperial Fleet in history, culminating in the construction and deployment of twelve Titan Ships, a series of massive battleships commanded not by human captains but by the ghosts of those former Imperial commanders who had proved most loyal to the Imperator.
Designed to operate autonomously, the Titan ships were huge, mobile fortresses with internal production capacity that, given sufficient resources could repair themselves and manufacture a wing of combat drones which could extend their own combat capabilities.
End of the Imperium
At first Hugo’s strategy met with great success as the Titan ships began pushing back rebel forces. However, the rebel commanders began cooperating to an unprecedented degree and, concentrating their forces effectively, were able to gain local superiority and defeat the Titan ships in detail, though at great cost in ships and personnel.
Eventually the Imperial Fleet, including the last three Titan ships, was pulled back to Centaurus Prime in a last ditch effort to defend the Imperial Capital.
The final battle took place in full view of the Imperial Palace and, as he watched one by one as his beloved Titan ships were crushed by the rebel fleet, Hugo made his final descent into lunacy.
But, before the last Titan ship was defeated, it withdrew from the battle and, much to everyone’s surprised, escaped the Centaurus Prime system via a wormhole of its own creation, a capability never before seen in a human ship. That ship vanished from Imperial space and was never seen again.
Meanwhile, the rebel fleet consolidated its victory. Hugo’s head was displayed on a pike before the Imperial Palace and most of the members of the Great Houses were murdered in their own homes and their ghosts permanently deleted.
The Imperium was no more.
The Collapse
Although the rebels celebrated their victory, the dissolution of the Imperium led to widespread economic chaos, as systems that were formerly dependent economically on Imperial trade suddenly found themselves trying to retool to become more self-sufficient.
Before long ships that had helped defeat the Imperium were mustered into raiding parties to take by force from neighboring star systems that which was needed to survive. Many systems simply descended into barbarism, unable to reverse the economic disaster that had overtaken them.
Many star systems, in order to prevent raids from neighboring systems, simply deactivated their jump gates and severed their ties with the gate network. This only hastened the inevitable economic collapse as trade dried up and those systems that depended upon it were simply unable to prevent it.
The Dark Age had descended.