I have recently begun to document all the historical grievances/friendships factions feel for each other. This will be a pretty exhaustive effort, and probably take a few more days at fastest. Below is a checklist of things to do as well as unanswered questions.

1. Start Italy Campaign. Document all historical friendships/grievances. DONE.

2. Start Europe Campaign. Document all initial historical friendships/grievances. DONE.

3. Play through Europe Campaign, destroying every faction except ones that can't emerge (Batavian Republic, Kingdom of Italy, Kingdom of Naples, Kingdom of Sardinia, Kingdom of Sicily, Papal States), let all other regions rebel. Document all historical friendships/grievances. DONE.

4. Play through Peninsular Campaign. Should be easy, considering how there's 4 factions.

4. Play through Multiplayer Italy Campaign etc.. There are additional factions in the MP campaign. 

5. Play through Multiplayer Egypt Campaign etc. This is necessary as the default singleplayer Egypt campaign does not have diplomacy available.

6. Play through Multiplayer Europe Campaign. This might just overlap with the standard, singleplayer campaign.

7. Play through Multiplayer Peninsular Campaign.

Questions:

Are the grievances generated random, semi-random, or fixed? I can only document things that are fixed, of course. The only way to test this, and I groan just thinking about it, is running the tests through multiple times.

Some of the grievances found make sense. Ireland and GB hate each other, for example. Most factions dislike France due to Napoleon's high-handed ambitions. But some don't make sense. How come Catalonia doesn't hate Spain? Catalonians have wanted independence from Spain for hundreds of years (and many still do). Why do people have historical friendships/grievances with Brittany, a country which hasn't existed for well over a hundred years by the time of NTW? These latter quirks makes me feel like some of the values generated may be random.