This is a beginner question (still trying to wrap my head around all the political aspects of the game)...
What is the benefit of holding a duchy, besides the prestige. I ask this because I am currently playing as a King and I'm over my demesne limit, so I'm just giving away titles to get myself under again. However, given the option of giving up either a duchy or a county, I can't see why I would give away the county. From what I understand, holding the county gives me the tax money directly. Holding the duchy, though... I can't really see how that benefits me besides the slight increase in prestige/month. Well, I guess also to limit the political power of some of the court. But beyond that, are there there any other benefits (particularly economic)?
Again, I'm still a beginner so maybe I'm misinterpreting something or getting something wrong. Any corrections are appreciated.
If find that as a king the best strategy is to hold 2 duchies (never more) and personally hold all counties in those 2 duchies. If possible, try to keep all vassals to one 1 county each, and give each duke control over all of his de jure area. I also don't usually worry about getting to my demesne limit as a king, but that's just me.
Doing that tends to minimize potential relation penalties with your vassals, making your realm a more stable place.
And don't knock that extra prestige bonus: a little bit each month add up over long period of time, which increases your overall score. That, and holding more titles increases your dynasty prestige, which makes your family more attractive to marry.
As Chipster got at, prestige is good. Its kind of the point of the game.
You arent really making a County vs. Duchy decision. A duchy title does not count toward the demesne limit. The demesne limit is only adding counties and any lower holdings (castles/cities/churches) if you have any. There is also a separate duchy limit for a King/Emperor. It is always 2. Therefor, you should set your demesne limit and keep 2 duchies.
To all the people that say create them for prestige I disagree!
I haven't done the math but I believe the average Duchy is made of 4 counties might be like 3.8 but lets say 4 for easy math.
If I have 4 vassal counties I get .40 prestige which is .10 times the 4 counties.
If I create a duchy I get .20 for the duchy and NOTHING for the counties since they aren't my direct vassals.
When I play I usually create all Bishoprics and sometimes cities. I "let" them create duchies, since I can't stop them, due to the fact I haven't already done it they will.
When they do that then its 3 counties at .10 each and one county that is now a duchy at .20 for a total of .50 for the same 4 counties. You will get the -25 modifier becasue they will want the other counties.
If its only 1 other county I just take it.
If its 2 other counties I can usually deal.
If its a larger duchy then I will either take it myself and adjust my demese or conform.
I would say though that only about 1 bishop will create his duchy title every 40 years so its not a big deal.
You will get far more prestige this way before you have to conform to duchies
You... what? What? I don't understand your line of thought at all.
First of all, duchies are independent of counties so creating a duchy title doesn't change one of your counties into a duchy. All four counties still produce 0.10 prestige.
Second, what's all this about bishoprics? Do you hold every county in your realm and then give them out sparingly to bishops? Do you have any idea how terrible an idea that is? You're either way over your demesne limit or far too small to have any need for vassals.
If that's not what you're doing then please explain it to me, I honestly cannot figure out what you're talking about.