At some point in time, Ghaul and the Consul overthrew Calus, and Ghaul became the Red Legion's leader. Later, the Red Legion sent their massive fleet of warships to the Solar System, where they were assisted by a member of the Nine in taking out the Last City's satellites. They then proceeded to attack the City directly, destroying the Tower and capturing the Traveler in a Cabal-manufactured "Traveler cage". From there, Cabal forces began occupying the City, executing anyone who stood in their way, as well as hunting down any Guardians that may have survived their initial attack. After occupying Earth, Cabal forces quickly began to spread throughout the rest of the system, specifically to Io, where they faced resistance from Taken, as well as Nessus, where they began a battle against the local Vex. Eventually, however, thanks to the Guardian responsible for slaying Oryx, as well as ending the SIVA Crisis, the forces of the City took back their home and pushed the Cabal out of the city, with Ghaul killing the Consul, and the Traveler awakening to break free from it's cage and killing Ghaul. However, the death of Ghaul did not completely destroy the Legion, as forces still remained on Io and Nessus, as well as in the European Dead Zone. Around this time, the former Cabal emperor Calus arrived in Nessus' orbit, and began recruiting members of the Red Legion, encouraging them to join his Loyalist forces aboard the Leviathan.
After their first ever defeat at the hands of the Guardians, Red Legion leadership became fragmented until the Valus known as Ca'uor stepped into the then vacant role of "Dominus" of the Cabal Empire. Under his command, Cabal forces were stationed on Mercury and Mars in an attempt to resupply their forces and establish a secure base somewhere in the Sol system. In a final, desperate attempt to reestablish Red Legion dominance in the system, Ca'uor led a full-scale invasion of the Leviathan, the massive prison ship of the previous Cabal emperor, Calus. Unfortunately for the Red Legion, Calus was assisted by the same Guardian who defeated Ghaul in pushing back the Red Legion and destroying their invasion fleet, as well as killing Ca'uor.
The Red Legion was seemingly permanently crippled after the death of Ca'uor, leaving leadership utterly devastated. However, this did not stop the Legion from sending a task force into the Tangled Shore during the emergence of the Scorn.
- Dominus Ghaul: Military Emperor of the Cabal Empire and the leader of the Red Legion.
- The Consul: Mentor to Ghaul.
- Thumos the Unbroken: One of Ghaul's "chosen."
- Grask, the Consumed: A Red Legion Phalanx who was consumed by the Taken.
- Val Ca'uor: Former Valus turned Dominus and leader of the Red Legion.