Since the Judges Guild subsector names were retained, I'd like to figure out how to work some of that in, even if the specifics of the JG versions (*everything else*) has been expressly de-Canonized.
For the two subsectors I started this discussion with:
The explanation for Tri-Empire Subsector can be retained simply because it is extremely vague: at some point in the distant past, three empires converged or were present in that subsector. With most of the history we know for the area starting in the 400s or so, but this area being close to the border of all three Imperia, that snippet is dead easy to place in the distant and poorly documented past.
Marla Subsector, so named for a modern state in the JG version (the Marlan Primate), can also have that factoid shoved into the past. There is no world by that name even in the JG version, so one of the three Empires referred to for the other subsector could have been some sort of charismatic religious state, and you can find their ruins and artifacts in Marla Subsector. Many of the worlds have architecturally distinct ruins identified as Marlan, and the subsector name stuck. Of course, the idea that the Marlans were one of the three empires may also be a red herring. They might have risen from the ashes of one of them, or been there before them.
I picked Kraxin because, well Krax is obviously JG material.
Bohemia, Dacia, Suebi (Suevi) are names of regions in central Europe, that long survived the peoples, and the kingdoms they founded.
Kraxin – Appears to be named for Apocraphya KRAX (JG:1120 / 1105 non-existent). The Krax Confederation formed 612-614, regions settled during the First Imperium as a exile colony. During t
he period 700 – 800 the Krax Confederation limited technological degeneration. As the Imperium expanded after 900, the polity became more unified. Imperial policy changed to be less expansionist to encourage development of buffer states. - JG Glimmerdrift Reaches p.4
It’s a good narrative but the wrong time frame. The Kraxian Confederation, named for a world formerly called Krax or for a leader, a religious or social movement, a corporation or some other historical reference, could have been an historical entity during the long night, formed circa -1614. (Amazing how typos carry down through history).
The Kraxin Confederation occupied parts of the Kraxin, Poonch, Even, Williamsburg and Sosie Subsector during its ascendance in the Long Night. The Kraxin are remembered as
the keepers of the clocks, those who held back the long night for as long as they could. But in the end darkness won, and the memories of those who fought to save civilization are just names in the stars.
To illustrate activity on the border of the Imperium, I referred to McKinney Integrated Timeline:
circa -1700 Human settlements scatter across the Gateway Domain. The first colonies in the Gateway Sector are likely on Tharver (0528), Bremen (1818) and Salur (0921). Gateway to Destiny, QLI, 2004, p. 11.
circa -1550 The last jump-capable ship in the Matarishan Federation in Ley Sector breaks down. Gateway to Destiny, QLI, 2004, p. 11.