Systems Army

A Systems Army was a type of military formation used by both the Grand Army of the Republic and the Imperial Army, although the meaning of the term changed completely between the Clone Wars and the Galactic Civil War.

Systems Armies in the Clone Wars
In the Clone Wars, the ten Systems Armies were major combat formations of the GAR, with an establishment strength of 294,912 Clone Troopers, composed of two Sector Armies, and each commanded by a Jedi High General, often a member of the Jedi Council. For instance, Mace Windu commanded Systems Army Alpha.

Systems Armies under the Empire
Under the Empire, the number of Systems Armies increased massively, so that by the time of the Galactic Civil War, they were typically subordinated to the Surface Marshal in charge of Army operations in a single Sector. Systems Armies were still commanded by High Generals, but these were now line officers rather than Jedi Knights, and they had oversight over a number of field Armies, each with an establishment of 193,644 combat troops and a total muster of 293,686 personnel, plus additional autonomous Corps HQs.

However, these Systems Armies would have been unrecognizable to veterans of the Clone Wars. The High General's primary responsibility was now to keep track of units and resources throughout the sector, and liase this information between the front-line Generals. The only force directly attached to his command consisted of a headquarters unit, only 1,855 men strong, and identical to those deployed with the subordinate field armies. This consisted of 784 support personnel, protected by one security company and six perimiter patrol platoons, and coupled with 200 ISB agents and three companies of COMPNOR observers. The same program of military buildup that had seen Systems Armies proliferate a hundredfold in twenty years had swolen their component elements to the point that they had superceded them as field formations.

Systems Armies were now parent formations whose front-line children had emphatically flown the nest, their only realy use being to make them presents of reinforcements or Navy support when required. Once the premier combat groupings of the Grand Army of the Republic. They had, effectively, ceased to exist as fighting forces.

Behind The Scenes
Systems Armes were introduced as elements of the Imperial Army in The Imperial Sourcebook, and retrospectively given their Clone Wars back-story only in Star_Wars_Insider #84. The authors of The Imperial Sourcebook may have intended for each Systems Army under the New Order to be a grouping of two field Armies plus autonomous Corps HQs, with two Systems Armies together forming an Imperial Sector Army; but the text does not completely exclude the possibility that a single nominal Systems Army formed the administrative interface between the Sector Army high command and all the field Armies and Corps operating in the sector.