Undocumented feature of Grand Inquisitors?

... or maybe I just don't read carefully enough?

Anyway, here is the deal:

Latest XL mod version, Irish/Early/Hard/MTWVI. Already late era.
I cornered my beloved Papacy to Sardinia. Cool. They already have zillions of points - thats not so cool but I will kill them later.

Anyway, I put all of my Grand Inquisitors (quite a few 4-7*!!!) to Sardinia, figuring that would be as good place as any and why should I burn my own population.

(Side question: If I can't crusade - as Irish in default - I should maybe deliberatelly burn my population get 0% zeal because zeal is no use for me anyway...? )

Anyway:
Next turn a huge peasant rebellion appears in Sardinia and puts the Pope into the castle, sieging... I must draw the conclusion that the reason for the rebellions was the presence of the inquisitors - when I removed them rebellions ceased.

In that case I and GI are even more powerful than I thought... at least with Catholic nations. Or this was only because the piety of the Pope was waaaay low due to frequent heresy trials?

Any ideas?

Hmm...

If the Holy Father had been exposed as an atheist, and the population consisted of a high proportion of Catholics then maybe that had an effect on happiness/the rebellion, but isn't this usually more relevant for the Governor of the province?

Yeah, burning the Pope for heresy is one of the true pleasures of MTW...

It was most likely the raise in zeal. Higher zeal means more revolts, right?

I'd suggest trying to locate whoever is assigned as Governor of Sardinia and hover the cursor over their piety rating.

The messages change according to the rating but the gist is that the general/gov's piety increases the numbers who would "come to his aid, if called upon". In other words, religious revolts.

In Shogun there was a thing whereby it's the faction leader who is first to be converted to Christianity, with the population following suit later. At the outset, loyalty takes a sharp dip but things improve as priests go about their work. There might be some leftover coding related to that - population 100% Cathy, highly zealous, governor is pious, Pope is Atheist. Not a good mix....