Me: "Hey, Sowers! You mind telling me why the fuck you've placed so many invasion ships near my main production center? You can't seriously be thinking-"
The Sowers has declared war on you!
Me: "Oh, so me graciously sparing you when you attacked me earlier wasn't enough to tell you how peaceful I-"
The Pilgrims has declared war on you!
Me: "Well fuck you, too! I take it my peaceful expansions into the galactic core irked you so hard when I got that large lava system before you-"
The Pilgrims have begun invading Lisul! (Lava system)
Me: "That's it. TOTAL WAR! BURN THE COFFERS! OUR SHIPS WILL BLOCK OUT THE SUNS!"
The United Empire has declared war on you!
Me: "I WILL BURN YOU ALL, SMELT YOUR SHIPS AND MAKE MY OWN GOD DAMN PLANET-SIZED IRON THRONE-"
The Automatons has declared war on you!
Me: "I WILL ENDLÖSUNG YOU ALL"
*Decades of fighting, the Sowers and Pilgrims annihilated, the galaxy under my control*
*The United Empire and the Automatons are both left with a single gas giant*
*Both systems surrounded by dozens of dreadnaughts and invasion fleets*
Me: "HOW DOES IT FEEL TO BE SO PUNY?! TO BE AT MY MERCY?! I SHALL TOY WITH YOU BEFORE YOUR INEVITABLE DEMISE!"
I had a similar match in Gal Civ II recently.
Krynn were being horribly expansionist and lining up starbases on my border to push it back and hopefully peacefully convert some of my planets. They literally only targeted me for this, none of the other AI, not even the more threatening ones.
So I declare war on the Krynn. Capture a few planets, crush their pitiful Defender and Sniper class fighters, and they ask for peace. I say no, because not all of their border planets are gone from my borders yet.
They surrender to the Altarians.
I declare war on the Altarians.
Torians and Drath declare war on me.
Drengin declare war on Drath, Torians and Altarians.
Thalans declare war on me, Altarians and Korx
Korx declare war on Altarians and Thalans
my custom race of ant people, the Myrmecians, declare war on me and the Korath.
The Korath declare war on everyone but me (Korx, Thalan, Torian, Myrmecian, Drengin, Drath, Altarian, Arcean)
The Arceans declare war on me and the Korath.
Everyone promptly surrenders to each other, leaving the Altarians controlling 85% of the board (on an IMMENSE galaxy size, this is no mean feat), the Arceans and I relegated to two small corners each.
And yet, I managed to defeat the Altarians and win a cultural victory.
Just in case your reading comprehension is bad:
Galactic Civilisations II