They were involved in the Battle of Bothawui where they faced a devastating defeat against the Republic defenders. The Imperial Army was also involved in the Sacking of Coruscant which brought about the Treaty of Coruscant that left both the Empire and the Republic in a Cold War.
After fleeing Korriban, the remainder of the Sith Empire stumbled on the jungle world of Dromund Kaas, after drifting in space for years. Once there, the first Grand Moff began a program to make a new Imperial military. He drafted all non-Sith of age into the army and established a training regiment that is still used to this day.
Over the years, they carved into the jungles of Dromund Kass, fighting off its hostile beasts to make room for the Empire's new capital. After the Imperial armada was completed, the Army and Navy were eventually deployed, in what is thought to be the greatest strategic invasion in galactic history, against the Galactic Republic opening the Great Galactic War.
A notable failure of the Army engagement was the Sith Empire's second attempt at taking Bothawui, where despite vast numbers, greater than the opposition, they failed thanks to the poor strategy of throwing their numbers at the enemy.
Since the Cold War their engagements have been reduced to peace keeping, as the Treaty of Coruscant forbids Imperial and Republic engagements, despite this they remain in active duty and are still deployed against the Republic in disputed territory.
By the time of the Cold War, the Army could be found in large numbers across Sith Space. Some of the troopers stationed on Korriban were corrupted by the planet's dark energies and went psychotic attacking their own comrades.
- Star Wars: The Old Republic, Threat of Peace Act 1: Treaty of Coruscant
- Timeline 5: The Battle of Bothawui
- Timeline 6: Onslaught of the Sith Empire