The setting for the Star Snakes campaign.
The campaign begins in the system of Flammarion, a part of the Spinward Marches and contains one of the last strong Imperium-centered space ports as you continue to head out spinward.
A J-6 (Jump 6) map of the area around the beginning of the campaign, centred on the system of Flammarion.
Red areas represent Imperium controlled space.
Image courtesy of travellermap.com