Note: X and Y are coordinates (light years on XY plane) relative to Terra at (0, 0)
Aldebaran neighbouring systems
|Recharge station(s)||Zenith, Nadir|
| Jump point
|Highest native life||Mammal|
|Ruler||Lord Hyung Li|
|HPG (Representative)||A (Precentor Trentus Milhaven)|
Alderbaran V - more commonly referred to simply as Aldebaran - was the fifth planet in the Aldebaran system.
Between 2310 and 2320 Aldebaran had applied for membership of the Duchy of Liao, the state formed by Emile Liao; this gave Aldebaran protectorate status equivalent to that of Arboris, the first world to join Liao's nascent state.
Aldebaran was was the target of the first Free Worlds League offensive of the First Succession War; a contingent of Free Worlds League Military including the Thirteenth Marik Militia launched an attack on the JumpShip drydocks located in the system, an attack that was both highly successful and notably brutal. In 2889 the commander-in-chief of the Free Worlds League Military and former commander of the Marik Guard, Admiral Lloyd Marik-Stanley, was killed in action on Alderbaran.
Aldebaran was one of a number of worlds to be hit by elements of an elite Free Worlds League Miliary strike force codenamed "Red Rover" between 2901 and 2910. Red Rover contained units from both the Defenders of Andurien and the Orloff Grenadiers and launched a series of raids targetting key Capellan Confederation Armed Forces supply depots, although the strong reserve forces established by Chancellor Otto Liao stopped the FWLM forces from remaining on any of the Capellan worlds.
By the end of the Third Succession War Aldebaran was the site of one of only eight BattleMech manufacturing plants left in the Capellan Confederation, although the plant on the planet was the smallest of those left. Aldebaran was one of the oldest settled worlds in the Confederation at this point, and had been a major industrial and commercial center for much of that time. Aldebaran's location made it a natural invasion route for those striking at the heart of the Tikonov Commonality, and this combined with the industry present on the world merited Aldebaran a high defense priority and a permanent military garrison.
Aldebaran was attacked numerous times during the Succession Wars, remaining a tempting target for both Free Worlds League and Federated Suns raids; as a result, it maintained several squadrons of AeroSpace Fighters and was the home base of Warrior House Ijori.
In August 3028 Aldebaran was one of the first Capellan Confederation worlds to be targeted as a part of Operation RAT, the Federated Suns' Fourth Succession War offensive against the Confederation. Defending Aldebaran at the time were the two battalions of elite warriors that made up Warrior House Ijori and sixteen assorted regiments of armor and infantry. The AFFS anticipated a difficult battle for Aldebaran, and assigned the combined forces of the Fourth Deneb Light Cavalry RCT, the Fourth Davion Guards RCT and Redfield's Renegades to conquering the planet.
The original plan for attacking Aldebaran called for both AFFS Regimental Combat Teams to land on the northern continent and grind House Ijori down, but updated intelligence led them to change this plan; upon learning that House Ijori had assigned one battalion to the northern continent and the second to the southern continent of Aldebaran, the commander of the Fourth Guards, Marshal Eugine Drivers, decided to split his forces as well. The Fourth Deneb Light Cavalry landed on the southern continent, while the fourth Guards landed in the north. The defending CCAF troops attempted to contest the landing, with AeroSpace Fighters meeting the invaders as the two seperate DropShip fleets entered Aldebaran's atmosphere; despite putting up a fierce resistance, the only significant casualty inflicted on the AFFS forces during the combat drop was when a disabled Thrush crashed into one of the Deneb Light Cavalry's Leopard DropShips.
The Fourth Guards were the first AFFS forces to see combat on the ground; having elected to land close to House Ijori's first battalion, close to the important city of Chouchu, the Fourth Guards 'Mech forces pushed towards the city from the south while the 1st Bellevue Armored Regiment and two battalions from the 17th Kestrel Mechanized Infantry advanced on Chouchu from the east. The Fourth Guards made little progress against the House Ijori forces despite their advantage in numbers, but did split the Capellan forces; this allowed the 1st Bellevue and the 17th Kestrel to advance into and seize Chouchu, the new Patton tanks of the 1st Bellevue romping over the vulnerable Capellan infantry forces. The news that Chouchu had fallen caused House Ijori to retreat, some of the 'Mech forces retreating west to waiting DropShips hidden in deep forest, while others broke south and attempted to regroup with the rest of the Ijori forces. The assault and battle cost the Fourth Davion Guards RCT only light casualties.
The battle for the southern continent was far longer and more troublesome than the battle for the north. Marshal Vernon Fredericks of the Fourth Deneb found himself being led on a merry chase around the southern continent by Major Thomasina Frou and the second battalion of House Ijori, along with their supporting elite infantry forces. Despite the numerous ambushes executed by House Ijori that inflicted numerous casualties on the AFFS forces, Fredericks declared the southern continent to be secure in early September.
As a result of Fredericks' declaration, the AFFS command soon ordered the mercenary unit Redfield's Renegades to leave Aldebaran. Unbeknown to the AFFS forces on Aldebaran, Major Frou had intercepted the orders transmitted to the Renegades, and elected to lead a daring ambush against them the night before their due departure date.
Frou led her forces through the Duocal swamp, threading them between the Second Battalion of Redfield's Renegades and a nearby mechanized infantry unit, the First battalion of the Corydon Regulars. Frou's target was the three DropShips assigned to transport the Renegades, and she led the House Ijori forces into position to attack the Renegades just after midnight. The ambush was a success initially, with the Renegades taking heavy losses and retreating rapidly back towards the DropShips, under constant pressure from the Capellan forces.
The CO of the Renegades' Second Battalion, Major Richardson, rallied his forces as they left the swamp; with firmer ground to operate on, the mercenaries managed to slow and then hold the Capellan forces for an hour, stopping their advance just a hundred meters from the Renegades' DropShips. This stand gave supporting AFFS forces an opportunity to reach the Renegades, with four regiments of armor and mechanized infantry arriving to surround the Capellan troops. Richardson called on Frou to surrender, but Frou was defiant until the last, refusing the Renegades' offer; the resulting battle lasted five hours, and saw the House Ijori forces destroyed.
With the loss of House Ijori's Second Battalion and the departure of the 1st Battalion, the will to fight amongst the remaining Capellan forces on Aldebaran collapsed, with organized resistance fading as the Federated Suns assumed control of the planet. The Fourth Deneb left Aldebaran shortly after to join the assault on Zurich, while the Fourth Guards remained until their relief arrived in December.
- 2271 - Inhabited world 
- 2341 - Terran Hegemony 
- 2366 - Duchy of Liao 
- 2367 - Capellan Confederation 
- 2571 - Terran Hegemony 
- 2596 - Terran Hegemony 
- 2750 - Terran Hegemony 
- 2764 - Terran Hegemony 
- 2765 - Terran Hegemony 
- 2771 - Amaris Empire 
- 2772 - Terran Hegemony (from September)
- 2783 - Terran Hegemony 
- 2784 - Capellan Confederation 
- 2822 - Capellan Confederation 
- 2864 - Capellan Confederation 
- 3025 - Capellan Confederation 
- 3028 - Federated Suns 
- 3030 - Federated Suns 
- 3040 - Federated Commonwealth 
- 3050 - Federated Commonwealth 
- 3052 - Federated Commonwealth 
- 3057 - Chaos March 
- 3058 - Chaos March/Capellan Confederation 
- 3063 - Capellan Confederation 
- 3067 - Capellan Confederation 
- 3075 - Capellan Confederation 
- 3079 - Capellan Confederation 
- 3081 - Republic of the Sphere 
- 3085 - Republic of the Sphere 
- 3130 - Republic of the Sphere 
- 3135 - Independent world 
- 3145 - Capellan Confederation 
3063 to 3067
- - At this point in time the 1st is operating at 25% of full strength, with 75% of their equipment featuring upgraded technology.
- House Liao (The Capellan Confederation), p. 139, "Aldebaran"
- Era Report: 3145, p. 39, "Inner Sphere Map - "
- Field Manual: 3145, p. VI, "Inner Sphere - 3145"
- Handbook: House Marik, p.16, "House Marik Founding "
- House Liao (The Capellan Confederation), p. 17, "Loosening Up"
- House Marik (The Free Worlds League), p. 90, "Marik Militia"
- House Marik (The Free Worlds League), p. 38, "The Great Compromiser"
- House Marik (The Free Worlds League), p. 39, "The Great Compromiser"
- House Liao (The Capellan Confederation), p. 107, "BattleMech Production"
- NAIS The Fourth Succession War Military Atlas Volume 1, p. 15, "Aldebaran"
- NAIS The Fourth Succession War Military Atlas Volume 1, p. 14, "Aldebaran Northern Continent map"
- NAIS The Fourth Succession War Military Atlas Volume 1, p. 16, "Aldebaran"
- Handbook: House Steiner, p. 13, "Lyran Commonwealth Founding " (obscured by Legend Pane, "...aran" visible)
- Handbook: House Liao, p. 17, "Capellan Confederation Founding, 2366"
- Handbook: House Liao, p. 13, "Timeline: Capellan Zone 2367"
- Handbook: House Liao, p. 25, "Capellan Confederation after Age of War "
- Historical: Reunification War, p. 159, "Inner Sphere - 2596"
- Era Report: 2750, p. 37, "Inner Sphere - 2750"
- Field Manual: SLDF, Inner Sphere - 
- Historical: Liberation of Terra Volume 1, p. 11, "Inner Sphere - 2765"
- Historical: Liberation of Terra Volume 1, p. 138, "Operation LIBERATION Wave 1 [July 2772 - December 2774]"
- Historical: Liberation of Terra Volume 2, p. 118, "Digesting The Hegemony"
- Handbook: House Liao, p. 31, "Capellan Confederation after First Succession War "
- Handbook: House Marik, p. 34, "Free Worlds League after First Succesion War  Map"
- Historical: Liberation of Terra Volume 2, p. 122-123, "Inner Sphere - 2822"
- Handbook: House Liao, p. 39, "Capellan Confederation after Second Succession War "
- Handbook: House Marik, p. 38, "Free Worlds League after Second Succesion War  Map"
- Handbook: House Liao, p. 40, "Capellan Confederation after Third Succession War "
- Handbook: House Marik, p. 42, "Free Worlds League after Third Succesion War  Map"
- Handbook: House Davion, p. 70, "Federated Suns after Third Succesion War  Map"
- Handbook: House Liao, p. 49, "Capellan Confederation after Fourth Succession War "
- Handbook: House Marik, p. 51, "Free Worlds League after Fourth Succesion War  Map"
- Handbook: House Davion, p. 71, "Federated Suns after Fourth Succesion War  Map"
- Handbook: House Davion, p. 76, "Federated Suns after War of 3039 Map"
- Historical: War of 3039, p. 133, "Inner Sphere - 3040"
- Era Report: 3052, p. 11, "Inner Sphere - 3050"
- Era Report: 3052, p. 23, "Inner Sphere - 3052"
- Era Report: 3062, p. 11, "Inner Sphere  Map"
- Handbook: House Liao, p. 60, "Capellan Confederation after Operation Guerrero "
- Handbook: House Marik, p. 54, "Free Worlds League after Operation Guerrero  Map"
- Handbook: House Davion, p. 78, "Federated Suns after Operation Guerrero  Map"
- Era Report: 3062, p. 29, "Inner Sphere  Map"
- Handbook: House Liao, p. 68, "Capellan Confederation after FedCom Civil War "
- Handbook: House Marik, p. 56, "Free Worlds League after FedCom Civil War  Map"
- Handbook: House Davion, p. 82, "Federated Suns after FedCom Civil War  Map"
- Jihad: Final Reckoning, p. 43, "Inner Sphere Map - [October 3067]"
- Jihad Secrets: The Blake Documents, p. 64, "Inner Sphere - 3075"
- Field Report: CCAF, p. 21, "Capellan Confederation Deployment Map"
- 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 - "
- House Liao (The Capellan Confederation), p. 107 - "Unit Deployment Table"
- Field Manual: Capellan Confederation, p. 119 - "Capellan Confederation Deployment Table"
- Field Manual: Updates, p. 33 - "Capellan Confederation Deployment Table"
- Field Report: CCAF, p. 15, "McCarron's Armored Cavalry Regimental Status"
- Era Report: 2750
- Era Report: 3052
- Era Report: 3062
- Era Report: 3145
- Field Manual: 3085
- Field Manual: 3145
- Field Manual: SLDF
- Field Manual: Capellan Confederation
- Field Manual: Updates
- Field Report: CCAF
- Handbook: House Davion
- Handbook: House Liao
- Handbook: House Marik
- Handbook: House Steiner
- Historical: Liberation of Terra Volume 1
- Historical: Liberation of Terra Volume 2
- Historical: Reunification War
- Historical: War of 3039
- House Liao (The Capellan Confederation)
- Jihad: Final Reckoning
- Jihad Secrets: The Blake Documents
- Map of the Inner Sphere 3130
- NAIS The Fourth Succession War Military Atlas Volume 1