I Corps (Star League)

SLDF - I Corps - 2750.png
I Corps
Formed 2571
Affiliation Star League
Parent Command First Army

Unit Description[edit]

The I Corps (also originally referred to as First Corps or the Terran Corps[1]) was a very large military formation that worked for the Star League Defense Force. The Corps' three Divisions consisted of twenty-seven regiments of frontline combat troops (principally BattleMechs, assortment of other vehicles/equipment/infantry) and additional auxiliary support formations.



The Corps was created by SLDF's newly appointed Commander-In-Chief Shandra Noruff-Cameron, who came up with the organization of Defense Force's formation in 2571.

The Corp's elements were drawn from the Terran Hegemony main military and were congealed into what became the I Corps after participating and training in a massive military exercise known as Unified Triumph Military Exercise in 2571. They and other newly formed League forces were out performed by the Star League's member-states' armies.[2] The troops improved over time and learned better to coordinate between one another by the end of that operation. The First Corps originally consisted of a Royal BattleMech Brigade supported by two Royal armor regiments and an independent Royal BattleMech regiment. The Second and Third Brigade consisted of the most loyal troops drawn from the new Star League's member states.[3]

Reunification War[edit]

Tensions between the Periphery Nations and the Star League continued to rise, with tariffs on Periphery goods failing to bring those nations to heel. So the First Lord Ian Cameron and his Star League Council began put into motion unspoken decision for war. Since the massive military exercises on the Periphery border had yielded much needed bases for the League. After Lord Ian would issue his Pollux Proclamation to the Periphery, he would begin move his realm and the Corp in motion. The 1st Corp and its sister Corps were placed at some of these bases which were on the border with the Taurian Concordat's between March of 2575 and December of 2576. The Corp's force would be part of campaign including the III, IV and the VI Corps and backed by an Auxiliary Corps of Federated Suns troops. The Corps and its sister commands would be placed in expeditionary force, commanded by General General Charles Mainstein Wexworth. However, Expedition's assembly was time slow goings. The Federation Suns troops moved ahead of the V's Star League Expedition, and ended up being ambushed in 2577 in the Tentativa system.

In May of 2578, the I Corp and rest of the Expedition would retaliate to the Taurian's preemptive strikes by beginning the invasion. In course of the initial fighting, the Concordat forces lose several key battles to League. However each of these fights the Concordat would send waves of suicidal Concordat infantry Regulars inflicting considerable amount of damage to the League forces. Taurians would slow down the invasion down to years, when it was originally projected as a six month campaign. Among other tactics, stubborn Taurians would employ would be terrorist style attacks, including poisoning water and blowing up SLDF forces in cities by placing bombs in sewers from under them. This would lead to Ian Cameron's announcement of the end of the use of the Ares Conventions by Star League forces in 2579.

The League's Taurian Campaign commander General Wexworth would be killed in battle on in 2582. Replacing him was General Amalthia Kincaid, whom conceives unorthodox plans to counter the Taurian guerrilla forces. However, this was short lived, after two years in command, General Kincaid would be assassinated by Taurian assassins. The Expedition would receive give command to brutal expedition commander of the Outworlds Alliance warfront, General Amos Forlough in summer of 2584. He would have I Corp and the other forces under his command to blockade worlds, and conduct planetary bombardment until these worlds fell finally to the Star League. Casualties began rise during the course of Forlough's tenure, including the seven month battle for New Vandenburg. The Concordat has been reduced by this time to less than half dozen worlds, and Forlough would be replaced by Lord Ian with Lord Damien Onaga. From January of 2590, he would lead the expedition at the head of the elite Star Guards and the war would end by 2596 with the surrender of the Concordat.[4][5]

Onaga used I Corps to conquer Brockway in 2590. Brockway was spared the immense death toll and destruction that many other Taurian worlds suffered during the War; this was due to Onaga changing the strategy employed on Operation BULL RUN, taking a very different approach to that ordered by Forlough. Onaga's approach to conquering Brockway saw him deliberately rotating troops[6] from I Corps and XI Corps[7] in and out of battle, giving them an opportunity to blood themselves, while limiting his campaign to purely military targets, rather than cities and civilian infrastructure. This made the conquest of Brockway a slower campaign than many previous planetary assaults, but inflicted far less damage, and with much of the planetary garrison having already been stripped away by the Taurian Defense Force to fight in other systems during earlier years of the war, the battle for Brockway was over by the end of November 2590.[6] The only major TDF unit on Brockway when the SLDF arrived, the Seventy-fourth Concordat Chasseurs, were destroyed by the SLDF during the invasion.[8]

Later Years[edit]

After the Reunification War, the First Corps took up station in the Terran Military Region. There they assumed the duties of the Star Guard Corps and became the sole defenders of Terra. The Corps was commanded from a Castle Brian located in Salinas, Kansas. During this time the soldiers of this Corps also served as testers for new equipment weapons manufacturers were hoping to sell to the SLDF. The Corps rotated through the twenty Castles Brian located on Terra as well, testing their readiness.[9]

The First Corps would later be stationed by 2764 in the Star League's Terran Military Region. Stationed in the Terran Hegemony, the Corps and its Regimental and Divisional elements would be among the first be struck down in the first year of the Amaris Coup. Only the 48th and 191st BattleMech Divisions would survive the initial assault of Rim Worlds Republics' assault and betrayal. In the later years of the Star League Civil War, the these two last elements of the I Corps would be destroyed before the conflict would end in 2779.[10]


Rank Name Command
Commanding Officers of I Corps
Major General Laurence Sheridan 2751 - 2758[9]
General Aaron DeChavilier 2758[9]
Major General Sir Laurence Sheridan 2758[9]



Composition History[edit]


1st Royal Division[7]
2nd Division[7]
3rd Division[7]


Independent Regiments

  • Notes: The no specific information notes how long or if the surviving elements of the 1st Corps long enough to fight in Liberation of Terra.[12]


The unit was originally known as the 1st Corp in the original text the Star League sourcebook. Details of their actions and demise have not been noted as of this writing.


Reunification War[edit]

  • All I Corps forces receive a +2 bonus to the Random Experience roll.[13]
  • All I Corps forces receive a +1 bonus when rolling to determine the availability of equipment, replacements and Advanced Components.[13]
  • All 1st Royal Brigade forces receive a +2 bonus when rolling to determine lance weight.[13]
  • All 2nd Royal Brigade may roll once per lance on the appropriate Royal/Terran Hegemony column when determining force composition.[13]
  • All 3rd Royal Brigade may roll once per lance on the appropriate Royal/Terran Hegemony column when determining force composition.[13]


  1. Historical: Reunification War, p. 29
  2. Star League sourcebook, p. 43, 47 - Unified Triumph Military Exercise, Pollux Proclamation & Battle Plans - Events leading to the creation of the then known as 1st Corps' formation from General Noruff-Cameron and Lord Ian Cameron's efforts building up unified force.
  3. Historical: Reunification War, p. 29
  4. Star League sourcebook, p. 47-49 - Reunification actions of the 1st Corp.
  5. Handbook: Major Periphery States, p. 19 Sowing and Reaping - The 5th Corps named as force being SLDF force targeted in the Day of Vengeance.
  6. 6.0 6.1 Historical: Reunification War, p. 91, "Cleanup"
  7. 7.0 7.1 7.2 7.3 Historical: Reunification War, p. 143, "Taurian Concordat Front [2586-2596]"
  8. Historical: Reunification War, p. 146-7, "Taurian Concordat Front"
  9. 9.0 9.1 9.2 9.3 Field Manual: SLDF, p. 38
  10. Star League sourcebook, p. 140 - Star League's Regimental/Divisional information for 1st Corps's status and its destruction.
  11. Historical: Reunification War, p. 164, "Lieutenant General Nicholas Cameron, SLDF (Ret.)"
  12. Star League sourcebook, p. 140 - I/V Corps listing show only two Divisions remain within the 2767-2779 time period. No mentions of when they were destroyed.
  13. 13.0 13.1 13.2 13.3 13.4 Historical: Reunification War, p. 181, "The Star League"