Military forces

Imperial:
Imperial Guard: All Imperial Guard regiments within the Revocatus sector are constantly fighting the forces of the Aventine subsector. For now they hold out, but if a large amount of reinforcements do not get through soon Revocatus’ fate cannot be assured.

Battlefleet Revocatus: There is a naval base in the Fallon subsector, which hosts the remarkably small Battlefleet Revocatus. The fleet have nothing significant enough to match the threat of Aventine and spend the majority of their time directly escorting ships along trade routes.

Knight Households of the Duquesne subsector: The Adeptus Mechanicus have deployed their Knights to protect the worlds which they are still holding. On occasions invasions are carried out in traitor held territory which from time to time are successful.
 
Non-Imperial:
Alpha Legion: A relatively large force of Alpha Legion Space Marines are carrying out attacks throughout the Revocatus sector. It were they who supported the local population of the Aventine subsector to rebel against their oppressive rulers.

Traitor Guard: All the worlds fallen to the Alpha Legion are now raising regiments to attack the rest of the Revocatus Sector. With access to military hardware from the conquered industrialised worlds the Traitor Guard forces of Aventine are more than a match for the Imperial Guard.

Chaos Raiders: These pirates loyal to the Alpha Legion have been able to isolate the Revocatus sector from Anargo not only by guarding the borders but also by occasionally carrying out pirate raids against ships in the Anargo sector. Khornate pirates carried out an attack on the world of Ludov where they introduced a xenos lifeform which causes major problems even many years after the invasion.

Orks: The original inhabitants of the Revocatus sector, the Orks have been driven off their worlds. Lonely pirate fleets still exist but they pose no major threat to the Imperium.