The best way to tech up castles

[Derfasciti]

How are castles (and towns) teched up (i.e. just population, certain buildings, etc.?) to provide better units and which way is the quickest way in your experience?


Thanks for any help.

[HoreTore]

Population. The tresholds for towns are:

2000 - large town
6000 - city
1200 - large city
2400 - huge city

For castles, it's less than half of that. I think fortresses are 4500, and citadels 9000.

[Derfasciti]

So it's exclusively based on population, then?

If so, what are the best ways to increase population?

[HoreTore]

Farms, health buildings, first level market and a chivalric governor all adds to pop growth.

Note that you have to build the new level of walls to get to the next level, ie. Large Stone Walls, Fortress, etc.

[Henry the Fifth]

You have to build the wall upgrade when the population reaches the right level in order to increase the tech level of buildings!

[Foz]

This can lead to some better discussion than just how to get new levels of city/castle. For instance, I've noticed a nagging problem with some castles in the game: They are very difficult to grow and tech up. Not all of them to be sure - just the ones that start at a particularly low base population.

Nottingham comes to mind. Nottingham IMO is a worthless castle. It starts with a very poor population, and typically will have to wait a LONG time to upgrade to the considerably-more-useful fortress level. On top of that, it starts with low castle military buildings, meaning you have to build it up really hard to even make it useful as a castle, not to mention have it ready for the Fortress-level buildings when you get there. Even all of that wouldn't be too bad... except that by the time you get it to being a fortress, the action has moved away from its area. Even if you don't own the entire British Isles when it upgrades, you're probably mostly there, which means you'll have closer places to the action to build troops. If you own the entire isles, this is even worse, since now you'd have to ship all the Nottingham troops to the action by sea. This trend continues for other low-population castles in other factions too: you often expand out away from them before they become very useful.

So then the question is, what should be done with such troublesome castles? In the case of Nottingham at least, even installing a bigtime chivalrous governor and building all farms ASAP hasn't been enough to ramp it up to usefulness when I need it, in my experience. I imagine it goes the same for other similar castles, but I haven't had time to play with them as much. As a result of what I've noted, I invariably turn Nottingham to a city as soon as possible - it's actually easier to get good fighting troops out of London, and Nottingham makes a good coastal trading city anyway. Is this the right move in general for such situations? If it is, what population makes a good cut-off, below which you should flip the castle to a city? Assume we're talking about factions that at least need some castles to wage war successfully - the ones that don't obviously will flip to cities as much as possible.