The Expansion Period was a conflict fought between the Stromma species and the Quesoth insectoid species long before 8 ABY. Although the Quesoth Soldiers used primitive weapons, the Stromma suffered considerably before surrendering.
In 8 ABY, Grand Admiral Thrawn of the Empire of the Hand requested to see the ancient and fragmentary recordings of the Expansion Period after Stromma Council Liaison Nyama mentioned the conflict, believing that as the Quesoth were an insectoid species, knowing their ancient military tactics could be useful in the Empire of the Hand's attack on the Quesoth homeworld of Quesoth.
The Expansion Period was mentioned in the 2011 novella Crisis of Faith, written by Timothy Zahn and included in Heir to the Empire: The 20th Anniversary Edition.
The Expansion Period was mentioned in the 2011 novella Crisis of Faith, written by Timothy Zahn and included in Heir to the Empire: The 20th Anniversary Edition.