At the request of Morat, I am opening this thread to research into the causes of rebelliousness.

Among the factors I have heard mentioned are:
- town loyalty: on claim is that if loyalty is 100% or higher (and there is no unrest) there will be no rebels in the province
- unrest
- presence of the "fog of war": it is claimed that rebels spawn out of sight; having a wider field of vision (e.g. through watch towers) reduces the likelihood of rebels spawning.

Morat is also interested in what types of rebels are spawned.