Earlier this year someone (possibly Procrustes? can't remember for sure) was experimenting with defensive sieges, upgrades, etc. He seemed to find one unit of Royal Knights & several organ guns an effective and virtually unstarvable garrison. If you wish to test your upgraded defenses, you may try leaving just those in a province to encourage invasion and then see if they will assault you.

Perhaps someone with a better memory will correct my errors, or you can search for the thread, as it had a lot of information relevant to the topic.

Ajax