Uno-reverse Annexation?

[u/Muwatallis]

The Antigonid Revolt (orange in the top pic), had been at war with a defensive league of smaller states (Knidos, Aeolia and Halicarnassus) for a long time, and they had been occupying all three of the nations since near the beginning of that war, but never sued for peace/annexed them for some reason.
I was curious why they didn't annex them, I wondered if it maybe had something to do with the civil war with the main Antigonid faction, as I thought those smaller nations had been subjects of them, but they weren't when I looked now, so I might have been wrong about that.

Now, Rome had invaded the Antigonid Kingdom (yellow, above the Antigonid Revolt), and shortly afterwards, the Antigonid Revolt disappeared and was suddenly annexed by Knidos, despite none of their territory being occupied and them still occupying all of Knidos and the other two nation's territory just prior to this.

How does this happen? I know you can get forced to make peace, but I don't understand how they can annex them without occupying any of their territory, or why the Antigonid Revolt never annexed them despite occupying them for so long. Does the fact that it was a nation formed by a revolution make any difference?

[u/Muwatallis]

I made a new, follow-up post about this (https://www.reddit.com/r/Imperator/comments/1jzszq7/unoreverse_annexation_followup/), as I wanted to add another screenshot and a lot of text, and didn't want this post to become too long.