Why move your capital?

[MythTrip]

Lets get the advantages of moving your capital, I have an old tribal capital I will likely move. Why should I do it?

[Merkatz]

The capital has more holding slots and is by the coast which would make it much more lucrative.

Which county to you hold and what's considered the capital?

[KG]

Or you can move from, say, Constantinople to an undeveloped county and start building your choice of holdings to give you whatever mix of cities and castles you prefer. Or temporarily move from the coast to a poorer inland province to hopefully avoid horrible disease (including vikings).

[that guy]

• You might want to up the tech somewhere else and can only use your techpoints on your capital county.
  
• Your current county has horrible tech compared to another one, and you need that tech in order to pass some laws.
  
• You are an emperor and have a powerful vassal king who desires your duchy because it's part of his de jure lands.
  
• Your current capital is the de jure capital of your realm, you already have a trade route in that county, you have a new ruler who has the business focus and you want to open a new trade route.

[Jerubius]

When you are trying to get something like shipbuilding up quickly, it can be useful to, at the start of each ruler's reign, change your capital to a coastal county, put a point or two into shipbuilding, and then switch back to your de jure capital.

[Star 'Sword Sage' Sil]

You're moving to a whole new duchy, and this new capital duchy has more counties in it. The capital duchy bonus would apply to more counties, thus making it more lucrative to be there.

[MythTrip]

Thanks what is capital duchy bonus exactly?

[Azunai]

the capital gets 50% bonus to levies and the other countes in the duchy get a 25% bonus if the holder is the same as the capital holder and independent (or 15% bonus if he's a vassal).

so basically, if you move your capital to a nice large duchy and kick out the counts from the other de jure counties and control all provinces in your duchy directly, you get a decent bonus to levies.

if your home duchy is small/poor (few holdings), you may be better off in the long run by migrating to a better duchy and building that up as your demesne.

for example, i recently started a 769 campaign as germanic high chief of saxony. the main duchy (saxony) isn't that impressive, so i decided to move my capital to hamburg and steal the duchy of holstein from it's original owner. holstein is a really nice duchy - 4 counties with a total of 22 holding slots (2 counties with 6 slots, the other 2 with 5) and all of them are coastal, so you can rake in some serious money once you start filling out those slots with cities and you have a vassal merchant republic nearby that puts trade posts in your counties.

[hurepoix]

In others games you would have penalities on tax perhaps levies for far away vassals. That would push player to move capital in a central position, or close to the most rich area. It seems not be like that at ck2 ... perhaps in a futur dlc to drain players money.

A favorable duchy at ck2 could be flanders ; 6 county, 31 slots. However in dark ages its a main target for vikings raiders, ethnic cultur is rather minor and duchy can easily be disputed by two major power.