18th Army (Star League)

18th Army (SLDF) 2765.jpg
18th Army
Affiliation Star League
Parent Command Star League Defense Force

The Star League Defense Forces 18th Army was assigned to operations within the Outworlds Alliance Territorial State.


Formed in the great expansion of the SLDF, the 18th Army replaced the II Corps and V Corps who had defeated and maintained control of the Outworlds Alliance since the Reunification War. At its peak the 18th consisted of twenty-four divisions which included six BattleMech divisions, fifteen infantry divisions and up thirty independent regiments.[1] The 18th faced a challenge in their garrison duties; the Outworlds Alliance had expanded to cover a large number of systems stretching out into the Deep Periphery, and the 18th was stretched thinly trying to cover such a large area.[2]

In 2765 most of the units assigned to the Eighteenth Army were in fact individual regiments that were used to garrison newly-opened systems, support Department of Mega-Engineering projects, and engage in exploration activities. The full Divisions and brigades of the Eighteenth were used to garrison more established systems near the Alliance's borders with the Federated Suns and Draconis Combine.[3]

When the Periphery Uprising erupted, the widely-dispersed deployment of the 18th was both a boon and a curse; many units were caught, isolated and alone, and wiped out by rebel forces. However, to engage the 18th the rebel forces were forced to disperse their own forces over a wide area, allowing many units within the 18th to survive the weeks and months before other SLDF formations arrived to reinforce them virtually intact.[2]

Like all Territorial State armies, the 18th initially attempted to stabilize tensions in the Alliance before Stefan Amaris's murder of Richard Cameron, suffering heavy losses in the assault on the Rim Worlds Republic and eventual recapture of the worlds of the Terran Hegemony. The Eighteenth Army was disbanded upon the collapse of the Star League.


Rank Name Command
Commanding Officers of the 18th Army (Star League)
General Son Ok Kim 2765[2]


Different per Unit.

Corps of the 18th Army[edit]




  • 2 BattleMech Divisions[1]
  • 9 Infantry Divisions[1]
  • 21 Independent Regiments[1]

The 18th lost eight Divisions and seven Independent Regiments outright as battlefield casualties, with another 2 Divisions and 2 Regiments lost to disbandment, leaving the 18th at 55% of its pre-Uprising strength when the ceasefire began in mid-2767.[2]


  1. 1.0 1.1 1.2 1.3 The Star League, p. 156, "Eighteenth Army"
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Historical: Liberation of Terra Volume 1, p. 45, "Eighteenth Army"
  3. Field Manual: SLDF, p. 211