A ' Glorious Expedition of Heroism and the Survival of the Race', as Queen Chrysalis said before her Equestria invasion.
The grudge between the changelings and the ponies has lasted for thousands of moons, countless wars have broken out between them. It wasn't until Chrysalis's reign that the changeling finally became close enough to completely engulf their hooves of tyranny over Equestria and its neighboring nations...
Moons after Equis entered the Age of Industrialization, the changelings began to grow their military secretly under Chrysalis's direct order. To counter the questionings by the League of Harmony, formed by Equestria and its allies, Chrysalis accepted their treaties to build a better world 'together'.
Then, out of silence. The changelings attacked.
Seizing numerous Equestrian cities within the first couple of weeks of the war, the Changeling Empire's forces were at their prime.
That was until the allies of Equestria joined in.
The Changeling Empire, six years into the war, was worn out, both by the continuous attacks by the allied forces and the shortage of supplies; the once undefeated Changeling Army was now on the brink of falling apart. In the final month of this war, the allied forces had pushed to the doorsteps of the Changeling Empire.
All surviving members of the Changeling Empire are expected to fight to their last breath, no matter their age and gender. Those who refuse to fight are to be marked as traitors and executed on the spot.
Chrysalis refused to surrender.
As she orders her army to make the final push...