The ruthless tyrant of Solaria Sector stands at the helm of her mighty war fleet in a struggle to brutally crush the lunar insurrection that threatens to liberate the Equestrian worlds from her reign of oppressive subjugation.
"In the past, countless ponies suffered on thousands of worlds, during the interregenum, the Long Night, when civilization was all but gone and the galaxy was under the rule of Discord. It took a thousand years' struggle by the Immortal princesses of Equestria to free us from it, and establish the Equestrian Hegemony across the star sectors that had maintained peace within the galaxy ever since.
Had not for our majesties, we would had all drowned in an eternity of anarchy and bloodshed, fallen prey to barbarism and regression. Like Princess Celestia's Suns the Hegemony was our light out of the darkness and decay. And now that light is being threatened by naive rebels who thought their way was the right way, blissfully ignoring what kind of universe they are living it.
Ultimately, for all its faults, the Equestrian Hegemony, or the so called 'Solar Empire' as the rebels like to deride, is a necessary evil. Yes, at times the rule is harsh, mired by corruption and unfairness, but at most times Princess Celestia's realm had protected its people from a hostile cosmos, and preserved peace and harmony across the galaxy for millennia. Without it, who could the subjects of the empire turn to to save them from the horrors that lurks beyond the borders and between the star-ways?
Let them call us tyrants, monsters, oppressors if they want, but whatever happens, whatever the price, the Long Night cannot be allowed to come again; Our majesty's empire Must. Not. Fall."
--- Admiral Bucephalus, Imperial Navy 2nd Fleet, Year 4210.
She banned Luna to the moon for a millenium, made Fluttershy cry, and threatened to send Twilight away from her friends in Ponyville. That's like the pony equivalent of being a tyrant (in real life, it'd only be major douchebag status).