Badger-fiend, ruling a human civilization, sent me to kill skink-fiend, ruling a goblin civilization. This is the first time I've seen a civilization without a site-home; according to sites and pops report, no one lived there, but when I got there I found an entire population acting like migrants ("Ask me when I get home!") including their war leader and the skink-fiend law-giver.
Apparently these fiends didn't much like each other in hell either, because within 10 years of escaping, they were both at war. Badger-fiend ran them all out of their only city, and they'd been hiding in the hills over 1000 years, raiding the city enough that badger-fiend couldn't completely claim it, even though he started building human homes and shops there.
I think I wiped out the only truly goblin civilization left in this world, but there are probably some left in the region, since the place still didn't revert to ruin. Oh well, job done.
EDIT: In all, the wars in this world have been pretty lame, at least on this continent. An elvish queen sent me after a general, but when I got to the fortress, he was the only one there. The civilization didn't even have another. He had a kill count comparable to the megabeasts, but still, it's just one goblin. I didn't even get the kill; my companion stabbed him in the head while he was busy shooting at me (and why does he get to home right the fuck in on him while I'm staggering in the dark, not even a direction indicator for all my badass spatial-kinesthetic sense?)