The Seswenna Expansion was a period between 3701 BBY and 3699 BBY. It saw the development of the Dustig Trace into the Hydian Way. This facilitated the settlement of new sectors in the Outer Rim Territories including the Grumani sector.

Worlds colonized as a result of this Expansion included Darkknell, Aquilaris Minor, Oranessan, Kamasto, Ventruun and Scelepas.