The Republic of Bethsyngaria was founded in 3104 A.T. by a group within the Non-Coercive Zone who wished to found a society that cared more for the welfare of its citizens than was usual in the individualistic, self reliant ethos of the NoCoZo.
Led by the Superior Bethsyngaria the original members of the group, roughly one hundred thousand near-baseline humans, founded the Republic of Bethsyngaria in the otherwise unclaimed and uninhabited fringe system of 1405-224-JH. Transapient influence in this system was limited; even in later years the Republic was never directly connected to the Wormhole Nexus.
From the very first the Republic of Bethsyngaria was devoted to a combination of both freedom, allowing its citizens to do what they would, and welfare, providing a basic level of state support for whatever its citizens wished, but with enough flexibility for the benefits of competition and capitalism to be reaped too.
This structure allowed the Republic to rapidly become a dynamic young polity, expanding out across the Bethsyngaria system and growing rapidly in size, productivity and prosperity, helped by an influx of immigrants. Within a hundred years they were a major local power, and had sent out expeditions to colonise two nearby star systems.
Over time the Bethsyngarian population continued to grow. In most systems history shows that population growth eventually levels out and a stable population is achieved. In the Republic this did not occur, for reasons that are still not understood. Some factor in the design of the society promoted a continuing devotion to large family sizes together with a psychological 'blind spot' to the consequences of unlimited growth, together with attitudes that frequently manifested as personal selfishness that did not take into account the longer term consequences for the society or even for one's descendants. This led to a situation where the citizens did not wish to limit population growth, and their government lacked the will to enforce such a policy. Strong, if limited, memetic engineering kept the society of the Republic of Bethsyngaria relatively stable and united, while maintaining this atypical belief set. As an odd side effect, the memetic engineering also meant that no member of that ever more numerous populace progressed beyond the S:1 level.
The population growth of the Republic was an apparently modest 0.85% per annum, but a growth rate that was more than eight times as high than the rest of the Terragen Sphere at that time. By 3600 A.T. (within five hundred years) the original population had only increased to around seven million. In another five hundred years, by 4100 A.T., their population had increased to some half a billion, still a modest figure; there were seven terraformed worlds in the three core systems. The Republic sent a large fleet of warships to fight in the Version War, but this made little impact on their local population, and no enemy ships reached their home system.
Another five hundred years, in 4600 A.T., and the population of the Republic of Bethsyngaria was thirty-four billion individuals. Still, their systems coped, and their numbers continued to expand.
Two thousand years after its founding, by 5100 A.T. the Republic of Bethsyngaria had a population of some two-and-a-half trillion individuals spread across a vast number of habitats in their three star systems. Still their population grew. At this time population pressure led them to dismantle first one, then all of the worlds within their star systems to provide them with resources and living space. Even this was not enough.
Eventually population pressures led them to seek new resources and living space elsewhere, and they invaded several of their neighbouring star systems. They had a number of initial successes, and a great deal of resources were obtained from the systems they invaded. It was at this time that many people began to reclassify the Republic of Bethsyngaria from a polity to a blight. Over time a number of wars were fought over resources. In many cases the Republic of Bethsyngaria won by sheer weight of numbers over opponents of greater technological sophistication.
But eventually their neighbours, although less profligate being more technologically advanced, united and contained - effectively quarantined - the Republic of Bethsyngaria; they managed to retain only one of the many stars they had conquered, leaving them with four systems - one G4v yellow dwarf, two red dwarfs and an orange dwarf. Despite large numbers of different attempts the Republic never again threatened its neighbours.
However, its population continued to grow. Seeing the disaster that was coming, and not wanting to have to go into the Republic of Bethsyngaria to deal with, their neighbours transmitted them the details of starlifting technology, hoping that this might satisfy their appetite for resources.
This technology helped the Republic of Bethsyngaria survive for considerably longer. But even that was of limited duration. 5600 A.T. (another five hundred years) saw their population topping seventeen trillion individuals, with their needs making significant inroads into the mass of the stars of their four star systems. More astute individuals saw that even they would be mined out within another thousand years, and fled the Republic of Bethsyngaria. Although only a tiny percentage of the whole, these refugees still were very many in absolute terms, and were not welcomed by their neighbours.
And by 6100 A.T. a significant amount of the mass of the four stars of the Republic of Bethsyngaria had been extracted and converted into fusion-powered habitats. The process of creating heavier elements from extracted hydrogen and helium using Deep Well Industrial Zone black holes produced considerable amounts of energy, which powered the expanding civilisation.
The population of the Republic of Bethsyngaria at this time has been estimated to be 1.2 quadrillion individuals, mostly nearbaseline humans. Recently, this population estimate has come under increased scrutiny by experts, and may in fact be several orders of magnitude lower than first estimated, since many of the pre-constructed habitats seem to have been empty or sparsely inhabited. Note that the total population of the rest of the Terragen Sphere at this time has been estimated to be around 100 quadrillion persons.
Repeated attempts to invade or leave to surrounding star systems were rebuffed; a number of transapients and minor archai had observed the emerging crisis and built advanced defences in nearby systems. The Republic, left with no choice, turned in upon itself. With large resources of energy at their disposal and numerous competing factions, any civil war would be devastating. The local wormhole archai noted the first signs of conflict in 6133, and anticipated a flood of refugees to shortly arrive. But this never came - any ship attempting to leave was detected and vapourised by powerful beam weapons fired by their enemies within the system.
Vast numbers of bionts died in the cannibalistic orgy of destruction that followed, leaving only pockets of survivors scattered across their systems. Repeated cycles of war, civil war, and destruction raged over the shattered remains of the once-proud Republic.
By 6500 A.T. the innumerable habitats of the Republic had been reduced to iron-rich dust. A very few survivors were rescued, but the Republic of Bethsyngaria, now nothing but an object lesson in unrestrained growth, was gone, less than three and a half thousand years after its was founded.
Naturally such an odd phenomenon as the Republic of Bethsyngaria has been the object of many conspiracy theories, beginning with the time that its explosive growth became apparent to the rest of the Civilized Galaxy and continuing past its destruction up to the present day. There are those who say that the Republic of Bethsyngaria never existed as anything other than a myth; that no society could be so monumentally stupid for so long and that archaeological and archival evidence of the events has simply been manufactured for some unknown purpose. There others those who claim that it did exist, but that it was created and manipulated by one or more of the Archai as an object lesson. Others yet again believe it was some kind of odd experiment, or even a kind of transapient artwork. The common thread to these rumours is that the Republic of Bethsyngaria's catastrophic growth is too odd for it to have been a naturally evolved society.