storming castles

[Hiro_Antagonist]

Hey there -- I have a couple of questions about storming castles.

When playing against the computer (Difficult AI), I seem to have a really hard time storming their castles. I can generally cost-effectively take their territories, eventually cornering them in their castle.

The problem is once they're there, I usually have very bad luck storming their castle -- especially if they've got some crazy archmage leader in there. But even without crazy mage leaders, I often have a hugely disproportionately hard time taking over the castles, even with vastly larger forces.

Are there any tricks? If I keep them holed up in their castle and keep applying seige over multiple turns, does that weaken them at all? Is there any sort of specific ability I should bring in my attacking force to help?

Or should I avoid the problem altogether by simply keeping them in their castle, mopping up remaining forces/territories, and snuffing out their dominion?

(I've been using Marignon recently, so I have inquisitors which should make that much easier...)

Thanks in advance for any answers.

-Hiro_Antagonist