Note: X and Y are coordinates (light years on XY plane) relative to Terra at (0, 0)
Cerberus neighbouring systems
The Cerberus system is home to at least one habitable world and as at 3145 was located in the Raven Alliance. During the Star League era Cerberus was a provincial capital within the Outworlds Alliance.
- 2571 - Outworlds Alliance 
- 2581 - Outworlds Alliance 
- 2583 - Outworlds Alliance 
- 2585 - Outworlds Alliance 
- 2596 - Outworlds Alliance 
- 2750 - Outworlds Alliance 
- 2764 - Outworlds Alliance 
- 2765 - Outworlds Alliance 
- 2767 - Outworlds Allliance 
- 2822 - Outworlds Alliance 
- 2864 - Outworlds Alliance 
- 3025 - Outworlds Alliance 
- 3030 - Outworlds Alliance 
- 3040 - Outworlds Alliance 
- 3050 - Outworlds Alliance 
- 3052 - Outworlds Alliance 
- 3054 - Outworlds Alliance 
- 3057 - Outworlds Alliance 
- 3059 - Outworlds Alliance 
- 3063 - Outworlds Alliance 
- 3067 - Outworlds Alliance 
- 3075 - Outworlds Alliance 
- 3079 - Outworlds Alliance 
- 3081 - Outworlds Alliance 
- 3085 - Raven Alliance 
- 3130 - Raven Alliance 
- 3135 - Raven Alliance 
- 3145 - Raven Alliance 
Cerberus was a core world within the Outworlds Alliance when Operation UNION HOLD began in 2581. With the intention of forcibly incorporating the Outworlds Alliance into the Star League following the mass rejection of the Pollux Proclamation in 2575 by the major Periphery states, the invasion of the Outworlds Alliance saw two corps of Star League Defense Force troops and a mixed brigade of DCMS forces begin systematically occupying Alliance worlds.
Both a regional capital and the most heavily industrialized planet within the Outworlds Alliance, Cerberus was an important world and a key target for the Star League Outworlds Alliance Task Force, under the command of General Amos Forlough. Cerberus had escaped attack until 2853 because of Forlough's plans to strike directly at Alpheratz, but after having his plans stymied for the past two years due to political interference from First Prince Alexander Davion of the Federated Suns and Coordinator Hehiro Kurita of the Draconis Combine along with the dogged resistance being offered by the Outworlds Alliance Militia and the Alliance population, Forlough lead a large force against the planet.
Cerberus had a strong garrison force, but Forlough landed two complete Star League Divisions on the planet in March 2853. The Fourth Division and Fifth Divisions, consisting of the Tenth through Fifteenth Brigades, defeated the Alliance forces tactically and rapidly overwhelmed them. Alliance doctrine called for infantry and armor forces to pin the Star League forces in place while the Alliance BattleMech forces acted as a mobile reserve. The Star League forces dropped directly onto Alliance militia positions, conducting a lightning assault that delivered a fatal blow to the militia on the first day of the invasion, allowing them to pick apart the Alliance Mech forces when they appeared on the second day.
Despite the heavy losses inflicted on them, Sadova and the Alliance forces reformed and resolved to battle the Star League forces for as long as they could, but even as the militia forces put up a valiant defense against the SLDF troops Forlough was already directing his troops to attack and lay waste to every factory, village, town and city on Cerberus, and thereby destroy the will of the population and the Alliance itself to resist.
Cerberus remained heavily contested right up until the end of the Star League campaign against the Alliance, and the slow grind of combat there extensively damaged both the Alliance and Star League forces. Forlough and the Tenth Brigade left Cerberus in 2583 to conduct slash and burn raids on Quatre Belle, Mitchella and Loparri and in 2584 the entire Fourth Division was redeployed to the war against the Taurian Concordat. The Fifth Division would continue to fight on Cerberus until it too was redeployed to the Taurian front in 2585, by which point three additional Star League brigades from V Corps would take over the fight - the Thirty-eighth and Thirty-ninth Royal Brigades and the Fortieth Brigade. The Outworlds Alliance Militia reinforced the defenders of Cerberus with those troops available; by 2584 all of the Alliance Grenadiers were fighting on Cerberus, along with the Santiago Carabiniers and elements of the Second Armored Division, and the entire Pitcairn Legion arrived in August 2584.
In February of 2585 First Prince Alexander Davion of the Federated Suns suggested to First Lord Ian Cameron of the Star League that the Alliance might be willing to negotiate if offered a fair proposal, while his son, Lawrence Davion, suggested options to Alliance President Grigori Avellar. Both Alexander and Lawrence Davion had negotiated with Avellar before - culminating in the Tancredi Accord in 2581 - and after four months of Davion brokering, both sides agreed to send emissaries to begin negotiations on Cerberus in June 2585. The initial Alliance position had two major demands; that the Alliance and it's people be granted the same freedom as any other Star League memberstate, and that Amos Forlough and his subordinates be tried on Alpheratz for genocide and war crimes. Ultimately, the two teams of negotiators came to an agreement in July 2585 while the Star League and Alliance Militia forces observed a truce, and with the peace treaty - named the Treaty of Cerberus - signed on the 25th of July and coming into effect on the 1st of August, the invasion of the Outworlds Alliance was over.
Reign of the Star League
To help reduce tensions between the populace the the Star League Defense Force garrison, the local SLDF commander allowed the garrison's infantry units to help planetary law enforcement and provide security for large events. The SLDF also allowed the local planetary miltia to face off against the garrison's troops for training purposes.
Cerberus Militia Forces
Outworlds Alliance Militia Forces
Outworlds Alliance Militia Forces
- - At this point in time, the Fourth Alliance Air Wing were deployed across Cerberus, Coraines and Jordan Wais. The 4th Alliance Air Wing was at 75% of full strength.
| Systems within 60 light-years (distance in light years)|
Closest systems first:
- Era Report: 3145, p. 39, "Inner Sphere Map - "
- Field Manual: 3145, p. VI, "Inner Sphere -  Map"
- Handbook: Major Periphery States, p. 147, "Outworlds Alliance after Age of War (2571) and at the Fall of the Star League (2750)"
- Era Report: 2750, p. 36, "Inner Sphere - "
- Handbook: House Davion, p. 48, "Federated Suns After Age of War -  Map"
- Historical: Reunification War, p. 106, "Reunification War: Outworlds Alliance Front Deployments (2581)"
- Historical: Reunification War, p. 123, "Cerberus And The Baby Killers"
- Historical: Reunification War, p. 126, "Year Five: Peace In Our Time" Cite error: Invalid
<ref>tag; name "H:RWp126" defined multiple times with different content
- Historical: Reunification War, p. 159, "Inner Sphere -  Map"
- Field Manual: SLDF, p. vii, "Inner Sphere -  Map"
- Historical: Liberation of Terra Volume 1, p. 11, "Inner Sphere -  Map"
- Field Report 2765: Periphery, p. 36, "Outworlds Alliance Militia Deployment Map - "
- Fiel Report 2765: Draconis Combine, p. 25, "Draconis Combine Mustered Soldiery Deployment Map - "
- Historical: Liberation of Terra, p. 98, "Outworlds Alliance - ] Map
- Historical: Liberation of Terra Volume 2, p. 122-123, "Inner Sphere - 2822"
- Handbook: House Davion, p. 54, "Federated Suns After First Succession War -  Map"
- Handbook: House Davion, p. 60, "Federated Suns After Second Succession War -  Map"
- The Periphery (sourcebook), p.156, "The Outworlds Alliance Sector"
- Handbook: House Davion, p. 70, "Federated Suns After Third Succession War -  Map"
- Handbook: House Davion, p. 72, "Federated Suns After Fourth Succession War -  Map"
- Historical: War of 3039, p. 133, "Inner Sphere -  Map"
- Handbook: House Davion, p. 76, "Federated Suns after War of 3039 -  Map"
- Era Report: 3052, p. 11, "Inner Sphere -  Map"
- Era Report: 3052, p. 23, "Inner Sphere -  Map"
- Objective Raids, p.46, "Map of Periphery States: The Outworlds Alliance Sector"
- Era Report: 3062, p. 11, "Inner Spher Map -  Map"
- The Periphery, 2nd Edition, p. 110, "Outworlds Alliance"
- Era Report: 3062, p. 29, "Inner Sphere Map -  Map"
- Inner Sphere, p. 97, "Near Periphery Kingdoms Map"
- Handbook: Major Periphery States, p. 150, "Outworlds Alliance (3067)
- Handbook: House Davion, p. 82, "Federated Suns After FedCom Civil War - "
- Jihad: Final Reckoning, p. 43, "Inner Sphere Map - [October 3067]"
- Jihad Secrets: The Blake Documents, p. 65, "Inner Sphere -  Map"
- Field Report: Clans, p. 28, "Clan Snow Raven & Outworlds Alliance Deployment Map - [August 3079]"
- Field Report: DCMS, p. 21, "Draconis Combine Mustered Soldiery Deployment Map - [August 3079]"
- Jihad: Final Reckoning, p. 63, "Inner Sphere - [3081 Map"
- Field Manual: 3085, p. vii, "Inner Sphere -  Map"
- Map of the Inner Sphere 3130
- Era Report: 3145, p. 11, "Inner Sphere Map - "
- Historical: Reunification War, p. 123, "Baby Killers Unleashed"
- Historical: Reunification War, p. 125, "Year Four: Slow Grind"
- Historical: Reunification War, p. 141, "Outworlds Alliance Front"
- Historical: Reunification War, p. 126, "Year Five: Peace In Our Time"
- Field Manual: SLDF, p. 215, "298th BattleMech Division"
- Field Manual: SLDF, Outworlds Alliance Military Region
- Field Report: Clans, p. 24, "Alliance Military Command"
- Field Manual: 3085, p. 128, "Deployment Table - 3085"
- Era Report: 2750
- Era Report: 3052
- Era Report: 3062
- Era Report: 3145
- Field Manual: 3085
- Field Manual: 3145
- Field Manual: SLDF
- Field Report 2765: Draconis Combine
- Field Report 2765: Periphery
- Field Report: DCMS
- Field Report: Clans
- Handbook: House Davion
- Handbook: Major Periphery States
- Historical: Liberation of Terra Volume 1
- Historical: Liberation of Terra Volume 2
- Historical: Reunification War
- Historical: War of 3039
- Inner Sphere (sourcebook)
- Jihad: Final Reckoning
- Jihad Secrets: The Blake Documents
- Map of the Inner Sphere 3130
- Objective Raids
- The Periphery (sourcebook)
- The Periphery, 2nd Edition