Imperator: Rome presents you with a number of challenges that are quite endemic to its central premise - to lead the Roman Imperium with as iron a fist as you can muster, more or less. Province loyalty is one of the things you're gonna have to keep an eye on.
Imperator: Rome province loyalty is a total signifier of how popular you are as a ruler in any of the game's numerous provinces, and gives you a general idea of how likely the locals are to rebel in this way or the other. Obviously, you want to maintain control over said province, so we've provided a guide on doing so.
How to Increase Province Loyalty in Imperium: Rome?</h2>
Starting from the very top, you're going to want to make sure that the province governor is loyal to you, and that the local population isn't starving or otherwise unhappy and miserable under your rule. You're also going to want to implement policies that suit said province, and attempt to increase regional stability by any means necessary.
We also suggest heavily reducing war exhaustion and minimising expansionistic advances, as well as attempting to convert the province to your religion in order to induce cultural assimilation. This sounds simple on paper, but the exact things you want to do to maximise success in any of these areas vary wildly on a case-by-case basis.
The bottom line is that you want the populace happy for them to be loyal. Going forward with that in mind should help you see a clearer picture in this regard. Good luck, though, as nothing is ever quite as simple as it sounds on paper.