[Saxon]

Any chance of spies or bards doing this to you? You have to patrol very hard to get rid of the very high levels. Depending on your magic, summoning some flying units could help you in this situation, they arrive exactly where you need them. I am sure you are also dropping your taxes manually as well, the auto tax feature does not handle agressive unrest attacks as well as a person can.

Good luck, I hope you are not too dependent on capital only troops...