How do priests raise dominion ?
Preaching has a chance of success every turn. In friendly dominion: (priest lvl)*20%. In enemy dominion: (priest lvl)*20-(enemy dom)*5%. If it succeeds, your dominion in this province goes up by 1. Temple in the province allows priests to preach as a priest 1 lvl higher. Every 5 temples you built increase max dominion spread lvl by 1. Inquisitors priest lvl count double in enemy dominion. Temples also spread dominion in nearby provinces. More details available here : http://www.maladjustite.com/dominion.
