They are exiles and outcasts. The unwanted refuse of an unforgiving empire, saved from the mass incinerator only because the authorities believed that they had found a better use for these maligned "undesirables".
But let us look at all this from the beginning. The world to which we have turned our attention was first discovered in the very early years of the XXII century. It soon became the best candidate for a potential secondary habitat for mankind. Thirty-one light-years distant, it would be effectively reachable by fusion-powered candle-ships. Although at that point still theoretical, such vessels would on average be able to reach a respectable fraction of light-speed in the undertaking of such a journey. A new world was effectively within reach of humanity, although not within easy reach.
The Imperium was establishing itself at this point, and the conquest of a new world was an attractive prospect to it self-congratulating elite. Luna City was revealed to be a hopeless bit of nonsense before excavation works were well and truly underway, and the prospect of trying to make something out of Mars was unappetising. Distant gold was valued over near-by dust, and the proper authorities soon began making plans for an unmanned recon mission to the new-found extrasolar world. All indications found it to be highly promising: within the "goldilocks zone", clearly terrestrial, evidently with an atmosphere and almost certainly in the possession of liquid surface water. The recon probe was indeed launched, and began its 150-year journey. It completed its extensive mission, and returned. Two thirds through its journey back, it was close enough to send its information to Earth in a tight-burst communiqué, thus shaving some decades off the time Earth had to wait for the information.
And what information it was! The planet was relatively Earth-like, with a breathable -- albeit thin -- atmosphere. Seeding the planet with the properly modified microbial forms could soon prepare it for algae bloom, kick-starting a process that would allow for further plant-seeding within decades. Humanity had found a second home, although it would hardly be a comfortable abode. The thin atmosphere could slowly be changed, but that would take centuries. For the time being, the planet would be "somewhere between Earth and Mars". There was surface water, but much less than on Earth. At sea-level, the air was as thin as in the Himalayas or the Andes. Becond that, one would need a an oxygen mask; and a little beond that, a pressure suit. Some mountain peaks were high enough to extend right through the thin atmosphere into the cold vacuüm. Even the temperature was unwelcoming, as the planet was quite literally in a position that would put it in between Earth and Mars on our solar system. A cold and dry place, compared to the comforts of Earth.
Which brings us to the colonisation scheme. It was rooted in many historical antecedents of sending undesirables to people an undesirable frontier. And the Imperium had many undesirables. The Greater Holocaust of the late XXI century had consumed billions, and for some time there had been a peace of the sort that one can built upon a mountain of corpses-- the Peace of an Augustus. But the second half of the XXIII century once more saw unrest tearing at the Imperium, followed by a pivot to more expansive and draconian governance. It is in these conditions that the Imperium learned that this far-off world was habitable but not very welcoming. The solution was obvious.
Throughout the early XXIV century, seeding ships were launched, and by the mid-way point of the century, the first of the great colonisation barges were sent out into the black. The colonists were hardly willing participants. They were simply given a choice between colonisation and death. So they embarked upon an unprecedented journey-- not that they experienced the century-and-a-half of it, which they naturally spent in suspended animation. When they awoke, the XXVI century had dawned, and they found a world that had been seeded with life for them. But thinly seeded. What had once been an Ordos desert with an air pressure one might find near the top of Mount Everest was now -- in its most
hospitable parts -- a Mongolian plain with an air pressure one might find in the high plateaus of Tibet. Coarse grass had taken root in the relatively temperate low-lands near the equator. Genetically modified crops could be planted, and certain animals would thrive in these plains.
And so began the colonisation of what the Imperium had named
Santuarium.
Nearly two centuries later, its inhabitants no longer call it that. The formalist Neo-Latin of the Imperium has mellowed into a comfortable colonialist patois. The planet of
Zanc Twari is still rough and dangerous frontier region, but it is also
home. The colonisation ships' powerful ordinance has been used to cut great canals in certain useful places, and the temperate low-lands have been effectively settled. There are several major settlements (over half a million inhabitants each) and many towns of over 50,000 souls. More far-flung regions are also being prepared for agriculture and grazing. It's not a life for the lazy, but it's life. One more wave of colonists has been sent from Earth, three decades after the first. The expected third wave never arrived. In fact, there has been no communication from Earth at all. The colonists of Zanc Twari have presumed themselves forgotten or discarded, and that suits them fine. The northern sea may be stormy, the highlands may be dry and deadly, the southern plains may be a frozen waste... but somewhere in between, the exiles have carved out a place for themselves.
Earth's orphans have found themselves adopted by the wild frontier.