A small, overstretched band of rangers who tried to keep order in the lawless space near the former Romulan Neutral Zone after the Romulan collapse.
The Fenris Rangers were a volunteer peacekeeping organization active in the late 24th century, operating in the region left without law or order after the Romulan supernova and the collapse of Romulan authority. They helped those in need where neither Starfleet nor any government would intervene. Operating as vigilantes rather than as an arm of any state, they relied on their own ships and their own judgment.
Seven of Nine joined the Rangers after her return from the Delta Quadrant, finding purpose there after being turned away from Starfleet. Her work brought her into conflict with Bjayzl, the crime boss responsible for the murder of Icheb. In 2399 Seven confronted Bjayzl on Freecloud while helping Picard's crew.
Seven also came to the aid of La Sirena while still flying as a Ranger. Her experience with them shaped the harder, more cynical outlook she showed during Star Trek: Picard.