Trojan Reach (1e)
It is called the Outrim Void. The Borderland. Wild Space.
"If the Spinward Marches is an isolated outpost to the rest of the Imperium¸ then the Trojan Reach is where the wilderness begins. The sector is an expanse of uncharted worlds and petty¸ backward barbarian kingdoms¸ a chaotic¸ treacherous zone of space teetering on the maw of the Great Rift. Somewhere¸ out there beyond the little one-world kingdoms and the failed Second Imperium colonies¸ are the ferocious and fearsome Aslan¸ unrestrained by the Peace of Fthair.