Corps/Legends

The Corps was perhaps the most useful and cohesive of the various high-level formations used by the Grand Army of the Republic and the Imperial Army - large enough to take most enemy worlds, it remained a key component in the armies of both the Clone Wars and the Galactic Civil War.

Army Corps in the Clone Wars
In the Clone Wars, a standard Army Corps consisted of four Legions of Clone Troopers, 36,864 men in total; it was commanded by a Clone Marshal Commander and a Jedi General. Four Corps in turn formed a Sector Army, implying a total of eighty Corps in the ten Systems Armies of the GAR.

However, a number of formations that would strictly be subordinate Legions within these Corps also used the term "Corps" in their designations. This may possibly reflect their growth into autonomous units of Corps size on their own, but at least some of them remained part of their parent Corps even when called "Corps" themselves - making it often very hard to know whether a unit was a Corps or a Legion in terms of its place in the hierarchy, or its number of troops. In practice, the situation was probably very fluid, with various legions in various stages of evolution, with extra troops, increasing autonomy from their parent Corps, and new Corps designations of their own.

One unit that was certainly a Corps was the 9th Assault Corps - because Commander Gree's 41st Elite Corps was one of its subordinate Legions. The 21st Nova Corps, the Galactic Marines led by Commander Bacara and Ki-Adi Mundu, were also probably a Corps within the 4th Sector Army at some point in their existence, but the precise status of the 327th Star Corps, led by Commander Bly and Jedi Master Aayla Secura is unclear.

Army Corps under the Empire
The Imperial Army was a much larger war machine than its predecessor had been, and composed largely of recruits from the civillian population rather than warrior clones. But Corps-level units retained a significance comparable to that which they had held during the Clone Wars. Many Corps had their headquarters aboard a massive KDY-Evkamar military transport, which served to coordinate subordinate units on various planets and warships acorss the sector, and a barracks for troops in transit from one assignment to another. The same ship could also carry an entire Corps into orbit for a planetary-assault deployment, a single Corps was regarded as a sufficient force to reconquer a planet that had thrown off Imperial rule - typically, in the face of odds of more than four to one.

There were four standard types of Corps - Line Corps, Armor Corps, Assault Corps and élite Atrisian Corps; and one Corps of each type formed a standard Army; but there were also autonomous Corps HQs, which functioned in a rather different way.

Line Corps
Composed of three Line Battlegroups and one Reinforced Battlegroup, this was essentially an infantry Corps with some embedded transport, artillery and armour support. It could field 48,514 front-line troopers from a total muster of 69,199 men, with 2,599 transports and at least 371 armoured vehicles

Armor Corps
An Armor Corps consisted of three Armored Battlegroups and one Mobile Battlegroup - a total of 48,192 soldiers and 74,794 men overall, with a minimum of 1,292 armoured vehicles and 5,128 transports. It was a heavy assault formation, designed to crush resistence, push forward through the enemy, and retain control of the territory it had taken.

Mobile Corps
A Mobile Corps was supposedly designed more for manoeuvre warfare than the sort of frontal assaults that an Armor Corps was typically deployed in; but in practice, its three Mobile Battlegroups and one Armored Battlegroup were little different in their overall balance of armoured vehicles and transports than the elements of an Armor Corps, and the two types of unit could be used interchangeably. A Mobile Corps mustered 48,504 combat personnel from a total of 71,615, with 5,548 transports and at least 1,113 armoured vehicles.

Atrisian Corps
With two Reinforced Battlegroups, one Armored Battlegroup, and one Line Battlegroup, an Atrisian Corps was an élite unit with a balance of firepower and infantry, with a better assault capability than a Line Corps, but more able to deploy troops in large numbers to hold terrain than an Armor or Mobile Corps.

Corps HQs
A Corps HQ consisted of fifteen senior adjutants and 388 support personnel, guarded by a security company and six picket platoons, and burdened with 50 ISB agents and three CompForce support platoons. There were, however, far more Corps HQs than there were Corps in the Imperial Army, as a Corps HQ, complete with a Major General in command, also served as the key military component of the typical planetary garrison.

Such HQs provided a basis around which a Corps-strength unit could be improvised in a crisis with whatever troops the Sector Army might be able to spare; the rest of the time, it was often said that they offered very pleasant assignments for very average Major Generals. Under normal circumstances, much of the garrison commander's duties were taken up with representing Imperial authority on his planet, and acquiring leverage over the civilian diplomatic, trade, and research personnel attached to his command; but he also had four battalions of troops at his disposal to maintain order and hold the line until help could arrive. While barely amounting to the equivalent of a single regiment, this detachment typically consisted of something like a battalion of Stormtroopers, two battalions of AT-ATs, and one of AT-STs, coupled with a Ground Support Wing of two TIE/gt squadrons, one TIE Bomber squadron and a TIE/fc spotter flight. This balance of forces gave the Corps HQ garrison an impressive combination of firepower, armour, reconnaisance and manouevrability for its size.

Behind The Scenes
The Corps organization of the Imperial Army was first described in The Imperial Sourcebook; the Army Corps of the Clone Wars, however, appeared only in Star Wars Insider #84.