XXXI Corps (Star League)

XXXI Corps.jpg
XXXI Corps
Unit Profile (as of 2784)
Parent Formation Thirteenth Army
Formed Unknown

Unit Description[edit]

XXXI Corps (or the Thirty-first Corps) was one of the seventy-two Corps that made up the Star League Defense Force. Prior to the collapse of the Star League XXXI Corps consisted of 5 divisions, 2 independent regiments and an independent aero wing.[1]


In 2764 XXXI Corps was part of the 13th Army, assigned to District 3 of the Lyran Commonwealth Military Region.[1] In some ways XXXI Corps was unusually specialised for an SLDF corps due to the high number of jump infantry units contained within the corps. Three of the five divisions within XXXI Corps were designated as jump infantry divisions, leaving the one mechanized infantry division in the position of training to secure and ground gained by the three jump infantry divisions. The one BattleMech division in XXXI Corps, the 438th BattleMech Division, was actually raised and supported by the Lyran Commonwealth, in part as a response to the formation and support of the 409th BattleMech Division by the Free Worlds League. This altered the composition of the 438th in comparison to other BattleMech divisions within the SLDF, with a high preponderance of Lyran machines - both the heavy and assault designs the Commonwealth was famous (or infamous) for, but also light designs such as the Commando.[2]

In the early 2760s the commanding officer of XXXI Corps was Major General Jason Quan, an officer noted for his high-risk, high-reward command style. Quan's attitudes led to him making friends and enemies in roughly equal measure, and he remained a polarising individual even as a corps commander. Quan had been removing those members of his command staff who disagreed with his management and leadership over time, but as late as 2764 some stubborn holdouts remained in post, making it difficult to get all of the elements of XXXI Corps onto the same page and hampering the response time of the Corps.[2]

Occupying a region along the border between the Commonwealth and the Free Worlds League complicated the supply chain for XXXI Corps, and while the active competition between the Lyran and League suppliers kept XXXI Corps well-furnished with consumables, shipments from the SLDF were slowed down by customs inspections. XXXI Corps wasn't a high priority within the SLDF due to the lack of Royal units within the Corps and XXXI Corps simply not being an exemplar corps, forcing the Corps to rely on 'Mechs, armored vehicles and aerospace fighters that were commonly available.[2]

When the simmering violence and rebellion building in the Periphery erupted with the New Vandenberg Uprising and subsequent Periphery-wide uprising in 2765 XXXI Corps was deployed into into the Periphery Military Region along with the rest of the 13th Army.[1]

The conflict in the Periphery inflicted significant losses on XXXI Corps; one complete division, the 178th Jump Infantry, was destroyed along with the independent 687th Artillery Regiment. Despite these losses, XXXI Corps began the Hegemony Campaign as one of the larger Corps within the Thirteenth Army.[1]

XXXI Corps lost almost three times as many casualties in the Hegemony Campaign as it had taken during the Periphery Uprising; two divisions, the Commonwealth Division and the 204th Jump Infantry, were completely destroyed along with the independent Tenth Heavy Assault Regiment, while the 133rd Jump Infantry Division had to be disbanded as a result of heavy losses. Elements of the 133rd subsequently joined the Draconis Combine and Capellan Confederation.[1]

Only the 196th Mechanized Infantry Division and the 1002nd Independent Aero Wing survived as fighting units to follow General Aleksandr Kerensky when he led the bulk of the surviving SLDF on the Exodus.[1]

Composition History[edit]



  • 438th BattleMech Division (The Commonwealth Division)
  • 196th Mechanized Infantry Division
  • 133rd Jump Infantry Division
  • 204th Jump Infantry Division
  • Tenth Heavy Assault Regiment
  • 1002nd Independent Aero Wing


  • 196th Mechanized Infantry Division
  • 1002nd Independent Aero Wing


  1. 1.0 1.1 1.2 1.3 1.4 1.5 The Star League, p. 146
  2. 2.0 2.1 2.2 Field Manual: SLDF, p. 164-165, "XXXI Corps"