I just backstabbed my oldest allies, the Flitt. They were a polity of traders and such that ruled a mere 5 star systems when I first popped onto the galactic stage. Seeing opportunity in the Xanalok's (my species) natural proclivity for war, they allied with me in the hopes of crushing the local tyrant empire, which I forget the name of. I, being an opportunistic Xanalok, accepted, and after acquiring a few weapons promptly annihilated said tyrants, who had the gall to attack my planets and demand tribute when most of their colonies were mere outposts on planets with no atmosphere. In the space they left behind, the Flitt grew, and at the demand of my home planet so did I. They set up an empire that spanned 15 systems, a big achievement for us at the time, and I expanded to about 10 or so. While they sold their wares to me through the trading route we had set up, I set about setting myself up as the new tyrant race in this sector, also making alliance with a particularly vicious race of religious fanatics called the Gnosh. I, unlike the Gnosh and Flitt, wanted perfect worlds, not the barren rocks they were content with, so where they expanded their domains, I did quests for them until I'd unlocked all the terraforming tools I needed to get all my planets to perfection. Then I set about improving all my colonies to max, which took quite a lot of money and time. By the end of it the Gnosh had colonized over 30 systems and seemed to be at war with the Flitt - and winning, from all the assaults they kept on sending at the Flitt homeworld. I didn't bother myself with that, however, and busied myself with crushing the little 5-system empires I found growing up in my territory, annexing their systems for myself. Then I perfected those planets. By the time that was done, the Gnosh had somehow taken over the Flitt home system, leaving them with little more than a collection of asteroids. I headed over to their systems in disgust, announced the breaking of our alliance, and conquered all their planets in less than 10 minutes.
Now I might turn my eyes to the Gnosh, who knows.
Spore