Note: X and Y are coordinates (light years on XY plane) relative to Terra at (0, 0)
|Beta Regulus II|
Beta Regulus nearby systems (3151)
|X:Y Coordinates||-201.451 : 276.407[e]|
The Beta Regulus II system was colonised at some point prior to the end of the Age of War. Beta Regulus II was removed from maps during the Third Succession War following the Beta Regulus Tragedy.
- 2571 - Lyran Commonwealth 
- 2596 - Lyran Commonwealth 
- 2750 - Lyran Commonwealth 
- 2765 - Lyran Commonwealth 
- 2822 - Lyran Commonwealth 
- 2864 - Lyran Commonwealth 
- 3025 - No record 
- 3030 - No record 
- 3040 - No record 
- 3050 - No record 
- 3052 - No record 
- 3057 - No record 
- 3063 - No record 
- 3067 - No record 
- 3075 - No record 
- 3079 - No record 
- 3081 - No record 
- 3085 - No record 
- 3130 - No record 
- 3135 - No record 
- 3145 - No record 
The Beta Regulus Tragedy
In 2899, a rogue planetoid, roughly one thousand kilometers in diameter, was detected on a collision course with the planet. Grimly named Grande Diablo, when all attempts to divert the planetoid's course failed, the panic-stricken Beta Regulan government desperately called for assistance in either evacuating the planet's population or somehow protecting it from the planetoid's imminent impact in 2901.
When word reached Tharkad, an emergency meeting of the Estates-General was held on Great X where a massive evacuation effort was already under-way. Unfortunately even with securing every commercial, military and privately-held JumpShip and DropShip possible during the ongoing Third Succession War, the evacuation of the entire population would have taken far longer than the time remaining until impact. Worse, revised astronomical projections indicated the planetoid would impact on the northern continent of Brasillia, one of Beta Regulus II's most densely populated regions. As the planet's people learned of their looming demise, world-wide panic took hold as it became clear that the few evacuees would have to be chosen by lots, as others hastily constructed bunkers, hoping to survive the impact. The situation grew so out of control that three Lyran Commonwealth Armed Forces infantry regiments were called in to help maintain order, as aid workers were provided with arms to protect themselves and lethal neurotoxins to "end suffering in the event of the unthinkable". 
Having successfully evacuated only two million people off Beta Regulus II, Grande Diablo finally struck on 12 October 2901. Unfortunately the strike would prove far more severe than expected, the shelters built using hasty projections based off nuclear attack models greatly underestimating the effects of the impact. As Grande Diablo's impact discharged a massive amount of material and heat into the air, it also triggered massive shock-waves that tore the planet's mantle apart. The scorching blast encircled the planet within hours, the heat having nowhere to escape but the insulating vacuum of space, the re-entering debris being superheated during its descent and slamming into the surface with incredible force. The assembled evacuation ships still in-system could do nothing but watch in horror over the next two days as Beta Regulus II and the four million people left behind died. Distress beacons from those bunkers that survived the initial impact disappeared as the crust-shattering seismic shock-waves encircled the entire planet, while the world's blue oceans and green continents became nothing but endlessly churning seas of boiling magma beneath debris choked skies.
Despite the sheer loss of life, the ongoing offensives of Free Worlds League and Draconis Combine in the Third Succession War meant that Archon Eric Steiner and the Lyran nation could barely spare the time to truly mourn those of Beta Regulus II, the tragedy becoming another footnote of the Succession War era.
| Closest 24 systems (23 within 60 light-years)|
Distance in light years, closest systems first:
- Handbook: Major Periphery States, p. 25, "Rim Worlds Republic At the Fall of the Star League "
- Era Report: 2750, p. 36, "Inner Sphere - 2750"
- Handbook: Major Periphery States, p. 18, "Rim Worlds Republic after Age of War "
- Handbook: House Steiner, p. 40, "Lyran Commonwealth after Second Succession War "
- Handbook: House Steiner, p. 47, "Lyran Commonwealth after Third Succession War "
- Handbook: House Steiner, p. 25, "Lyran Commonwealth after Age of War "
- Historical: Reunification War, p. 158, "Inner Sphere Map "
- Historical: Liberation of Terra Volume 1, p. 10, "Inner Sphere - 2765"
- Handbook: House Steiner, p. 36, "Lyran Commonwealth after First Succession War "
- Handbook: House Steiner, p. 56, "Lyran Commonwealth after Fourth Succession War "
- Handbook: House Steiner, p. 59, "Lyran Commonwealth after War of 39 "
- Historical: War of 3039, p. 133, "Inner Sphere - 3040"
- Era Report: 3052, p. 11, "Inner Sphere - 3050"
- Handbook: House Steiner, p. 61, "Lyran Commonwealth after Clan Invasion "
- Era Report: 3052, p. 23, "Inner Sphere - 3052"
- Era Report: 3062, p. 11, "Inner Sphere Map "
- Era Report: 3062, p. 29, "Inner Sphere Map "
- Handbook: House Steiner, p. 70, "Lyran Commonwealth after FedCom Civil War "
- Jihad Secrets: The Blake Documents, p. 65, "Inner Sphere "
- Field Report: DCMS, p. 21, "Draconis Combine Mustered Soldiery Deployment Map - August 3079"
- Jihad: Final Reckoning, p. 63, "Inner Sphere Map - [March 3081]"
- Field Manual: 3085, p. 127, "Inner Sphere Map - [October 3085]"
- Map of the Inner Sphere 3130
- Era Report: 3145, p. 11, "Inner Sphere Map - "
- Era Report: 3145, p. 39, "Inner Sphere Map - "
- Field Manual: 3145, p. VI, "Inner Sphere - 3145"
- Handbook: House Steiner, pp. 46-48 "History of the Lyran Alliance - Third Succession War (2866-3025) - The Combine Front - The Beta Regulus Tragedy"
- House Steiner (The Lyran Commonwealth), p. 90 "Sociopolitical Structure - The Estates General"
- Era Report: 2750
- Era Report: 3052
- Era Report: 3062
- Era Report: 3145
- Field Manual: 3085
- Field Manual: 3145
- Handbook: House Steiner
- Handbook: Major Periphery States
- Historical: Liberation of Terra Volume 1
- Historical: Reunification War
- Historical: War of 3039
- House Steiner (The Lyran Commonwealth)
- Jihad: Final Reckoning
- Jihad Secrets: The Blake Documents
- Map of the Inner Sphere 3130