When Friends Attack

[ManAgainstTime]

I am wondering if this has happened to anyone else or if anyone knows why it happened. I was currently at war with two civilizations (Charlemagne and Gilgamesh). I was friendly with Churchill, and I think Annoyed with Wang Kon. I recently took over an entire island colony from Gilgamesh. The resistance time was obscene (like 15+ turns or something) for each of the 3 larger cities that were on this island. Mostly because I like playing a more fun game, and also because I didn't really care to have to defend this colony while waiting for the resistance period to be over, I had the option to liberate them; so i did.

The turn after this, Churchill and Wang Kon both declared war on me with I am pretty sure the same message, something to the effect of, "We are tired of your treachery."

I mean I am not winning by what I would consider a lot (I think like 3100 points whereas Charlemagne has in the 2000's and prior to war Gilgamesh was nearing 2000). It's late game (1920), I have one legendary culture city and no others really that close. I am just wondering why, what I can only assume, liberating this island caused a Friendly nation and another nation to declare war.

Any help or insight on this would be greatly appreciated.

 

[ManAgainstTime]

Forgot to mention! I am Lincoln.

 

[Seraiel]

Having vassals can put AI into dagger-mode, I've also already seen this. In your case, you freeing that colony probably caused an instant rise in AI's paranoia, so they jumped directly into war afterwards. The drop of relations (you and your vassal get combined diplomatic stance) helps with this.