XII Corps (Star League)

XII Corps.jpg
XII Corps
Unit Profile (as of 2784)
Parent Formation Ninth Army
Formed Unknown

Unit Description[edit]

XII Corps (or the Twelfth Corps) was one of the seventy-two Corps that made up the Star League Defense Force. Prior to the collapse of the Star League it consisted of 4 divisions and 6 independent regiments.[1]


In 2764 XII Corps was part of the 9th Army, assigned to District 2 of the Free Worlds League Military Region. They were largely based in the Abbey District. In fact the Twelfth Corps was the only military force of note in the area, which left the defense of many systems up to their component units. The soldiers of the Twelfth took this responsibility seriously. They patrolled the Free Worlds League/Lyran Commonwealth border as well as the Free Worlds League/Rim Worlds Republic border. They sent several recon missions into Rim Worlds Republic space, and found that the Republic units they met were overstrength. The SDLF High Command didn't view this as cause for concern however.[2]

Unlike other SLDF units in the Free Worlds League, the Twelfth Corps enjoyed a good working relationship with the population. In fact local military contractors would supply the Twelfth's units before they would supply FWLM units.[2]

When the simmering violence and rebellion building in the Periphery erupted with the New Vandenberg Uprising and subsequent Periphery-wide uprising in 2765 XII Corps was deployed into the Periphery Military Region along with the rest of the 9th Army.[1]

The resulting combat and terrorist actions within the Periphery Military Region inflicted relatively light damage on XII Corps compared to other Corps within the 9th Army; two of the Corps' independent regiments were lost, but the bulk of the Corps survived intact. XII Corps went on to fight in the Hegemony Campaign which inflicted greater damage on the Corps than the Periphery Uprising; the 32nd Infantry Division was lost, along with another independent regiment, the 22nd Light Horse.[1]

When General Aleksandr Kerensky led the bulk of the SLDF on the Exodus the majority of XII Corps followed him; only the 52nd Heavy Assault Regiment chose to stay in the Inner Sphere, joining the Draconis Combine.[1]

The final fate of the Ulysses S. Grant Division is currently unknown; while there is no record of the Division having been lost or disbanded during the Periphery Uprising, there are no records of it joining in the Hegemony Campaign, or of it leaving on the Exodus.[1]

Composition History[edit]

Unit 2764 2765 2766 2767 - 79 2784 Note
Independent Regiments
15th BattleMech Division[3]
151st Royal BattleMech Division[3]
32nd Infantry Division[3]
13th Royal Mechanized Infantry Division[3]
Independent Regiments
32nd Royal CAAN Marine Regiment[2]
13th Light Horse Regiment[2]
22nd Light Horse Regiment[2]
502nd Battle Regiment[2]
52nd Heavy Assault Regiment[2]
189th Heavy Assault Regiment[2]


  1. 1.0 1.1 1.2 1.3 1.4 The Star League, p. 142
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Field Manual: SLDF, p. 118
  3. 3.0 3.1 3.2 3.3 Field Manual: SLDF, p. 119