This is a list of formations of the ground forces of the Sith Empire. It goes down to mainly the field army level, not all the way down to every battalion of every regiment of every division. The list is spread among several years of the Great Galactic War, as over time, the organization of the Army was drastically changed.
For Imperial Armada order of battle, see list of Imperial Navy formations during the Great Galactic War.
3,681 BBY[]
In the year that the war began, 3,681 BBY, the Imperial Army was divided by the general staff into four army groups, with five armies each. They included Army Group North; assigned to invade the northern quadrant of the galaxy, Army Group South; which was assigned to take the southern quadrant, Army Group Center; which would move through the center of the galaxy, and Army Group Reserve, which provided reserve troops to replace the casualties of the other three army groups. Reserve also garrisoned captured worlds. At the time of the beginning of the invasion, the Imperial Army had a total of 988,794,432 troops, almost a billion men.
- Army Group North
- 1st Army
- 2nd Army
- 3rd Army
- 4th Army
- 5th Army
- Army Group Center
- 6th Army
- 7th Army
- 8th Army
- 9th Army
- 10th Army
- Army Group South
- 11th Army
- 12th Army
- 13th Army
- 14th Army
- 15th Army
- Army Group Reserve
- 16th Army
- 17th Army
- 18th Army
- 19th Army
- 20th Army
3,675 BBY[]
By 3,675 BBY, the shock of the invasion had passed and the Empire's advance was stalling. Also, heavy casualties were taken, and were increasing. This resulted in a reorganization and vast expansion of the Imperial Army's order of battle. The army groups were replaced with army corps, a total of six corps with each having four field armies. In addition, two shock groups, consisting of three shock armies each, were formed as well, which were made up of elite units. This year, the army had a total of some 1,195,436,921.
- 1st Army Corps
- 1st Army
- 2nd Army
- 3rd Army
- 4th Army
- 2nd Army Corps
- 5th Army
- 6th Army
- 7th Army
- 8th Army
- 3rd Army Corps
- 9th Army
- 10th Army
- 11th Army
- 12th Army
- 4th Army Corps
- 13th Army
- 14th Army
- 15th Army
- 16th Army
- 5th Army Corps
- 17th Army
- 18th Army
- 19th Army
- 20th Army
- 6th Army Corps
- 21st Army
- 22nd Army
- 23rd Army
- 24th Army
- 1st Shock Corps
- 1st Shock Army
- 2nd Shock Army
- 3rd Shock Army
- 2nd Shock Corps
- 4th Shock Army
- 5th Shock Army
- 6th Shock Army
3,668 BBY[]
In 3,668 BBY, the Empire had made little progress, and it's gains were lowering each year. The Galactic Republic was regaining it's strength, and the Dark Council knew they needed to end the war quickly. A new reform throughout the army was issued, which, at the time, was at 1,836,729,482 personnel. The army groups were again introduced into the army command structure, though this time, they were organized based on the regions that the Empire had to defend from the Republic advances.
- Army Group Inner Rim
- Army Group Outer Rim North
- 8th Army
- 9th Army
- 10th Army
- 11th Army
- 12th Army
- 13th Army
- 3rd Shock Army
- Army Group Outer Rim South
- 14th Army
- 15th Army
- 16th Army
- 17th Army
- 18th Army
- 19th Army
- 20th Army
- 21st Army
- 4th Shock Army
- Army Group Mid Rim
- 22nd Army
- 23rd Army
- 24th Army
- 25th Army
- 26th Army
- 5th Shock Army
- 6th Shock Army
3,662 BBY[]
As the war neared an end, the Empire had prepared for a final offensive into Republic territory before it could regain it's ground. More conscripts were introduced into the Imperial Army and Navy.