A demesne is a character's collection of personal holdings. Such holdings may either be counties or baronies. A ruler's capital is an important part of their demesne.
A character's demesne (pronounced /dɪ'meɪn/, almost but not quite like "domain") will usually provide the majority of their income, as well as a decent amount of levies (both from land personally held and from vassal barons). It is within one's demesne that most construction occurs, including construction of new settlements in county empty slots.
Each ruler (except nomads) has a demesne limit, and exceeding it causes a penalty to taxes and levies. This limit is what forces rulers to distribute power to vassals rather than directly controlling their entire realm. A ruler's demesne limit is based on tier, personal and spouse stewardship, succession type, and centralization law.
直辖领上限
Nomadic rulers do not have a demesne limit. Instead, Khagans will be increasingly pressured to give out excess nomadic counties (defined as counties with 0 or 1 settlement) to vassal clans (or to start a new clan), as excess counties lower clan sentiment, which lowers vassal khans' opinion towards the Khagan. If the Khagan continues to hold onto too many counties, a minor clan can rise up in rebellion to force the Khagan to recognise it as a major clan. (Unless the realm already has 9 clans) The Clans screen will indicate whether a Khagan needs to give out nomadic counties. However, while nomads are in control of holdings to carry out pillages, their liege tax is reduced until the pillages have destroyed the holdings.
When a ruler is over their demesne limit, they suffer penalties due to inefficiency:
- Reduced opinion from vassals (-10 per settlement over limit)
- Reduced demesne levies, except in the capital (-20% per, up to -90% with the 5th)
- Reduced demesne income (-20% per, up to -90% with the 5th)
- Reduced tax from vassals (-20% per, up to -100% at 5 over)
There is a 2-month grace period when a ruler goes over their limit due to acquiring new titles. However, if a ruler goes over their limit due to a reduction in stewardship skill, the penalties kick in immediately.
The demesne limit is (the [math]\displaystyle{ \lfloor x \rfloor }[/math] notation refers to rounding [math]\displaystyle{ x }[/math] down to the nearest integer):
[math]\displaystyle{ DemesneLimit = \left\lfloor \left(RankBaseDemesne + StewardshipBonus\right) \cdot GavelkindBonus \right\rfloor + LawBonuses }[/math]
Gavelkind
Gavelkind Bonus = 1.3 (+30%) if you are under Gavelkind or Elective gavelkind succession law, 1 otherwise.
Rank
Each rank has a base demesne value:
| Rank | Base demesne | Notes |
|---|---|---|
| Baron/Count/Duke | 1 | |
| Great Duke | 2 | A "Great Duke" is a Duke with 2 or more duchy titles. |
| King | 3 | |
| Emperor | 4 |
Unlike feudal lords, Patricians have different base demesne sizes. The base is 2 for a patrician and 3 for a doge, no matter what rank title they hold.
Stewardship
The stewardship bonus is (in case of polygamy, only the primary spouse's stewardship is used):
[math]\displaystyle{ StewardshipBonus = 0.15 \cdot \left(PersonalStewardship + \left\lfloor {\frac{SpouseStewardship}{2}} \right\rfloor\right) }[/math]
Here is a table of the [math]\displaystyle{ PersonalStewardship + \left\lfloor {\frac{SpouseStewardship}{2}} \right\rfloor }[/math] values required to achieve a certain increase in demesne limit relative to the limit you would have without Gavelkind and with 0 stewardship (note that this is different from the stewardship bonus, since the actual stewardship bonus is multiplied by 1.3 in the case of Gavelkind):
| Succession | Rank | +1 | +2 | +3 | +4 | +5 | +6 | +7 | +8 | +9 | +10 | +11 | +12 | +13 | +14 | +15 | +16 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Not Gavelkind | any | 7 | 14 | 20 | 27 | 34 | 40 | 47 | 54 | 60 | 67 | 74 | 80 | 87 | 94 | 100 | 107 |
| Gavelkind | Duke | 4 | 9 | 14 | 19 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 66 | 71 | 76 | 81 |
| Gavelkind | Great Duke | 3 | 8 | 13 | 18 | 23 | 28 | 33 | 38 | 44 | 49 | 54 | 59 | 64 | 69 | 74 | 79 |
| Gavelkind | King | 1 | 6 | 11 | 16 | 22 | 27 | 32 | 37 | 42 | 47 | 52 | 57 | 63 | 68 | 73 | 78 |
| Gavelkind | Emperor | 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 46 | 51 | 56 | 61 | 66 | 71 | 76 |
This table can be computed using [math]\displaystyle{ x = \left\lceil\frac{\frac{RankBaseDemesne+k}{GavelkindBonus} - RankBaseDemesne}{0.15}\right\rceil }[/math]
Tribal
Tribal rulers get a +2 bonus to their demesne, at a cost of -10 to their vassal limit.
Law bonuses
Centralization Bonus depends on the Centralization law, available to dukes and above:
| Level | Decentralized | Low Centralization | Medium Centralization | High Centralization | Centralized |
|---|---|---|---|---|---|
| Bonus | +0 | +1 | +2 | +3 | +4 |
With the 
Conclave DLC, absolutism (all council laws in ruler's favor) gives +2 to demesne limit. Tribal rulers may attempt to get this bonus only after reaching Absolute Tribal Organization, as it is only then can they propose to reclaim powers.
Breakdown
The in-game tooltip breakdown may be confusing, as values are rounded as integers for display, but formula uses float values behind.
Here's an example illustrating the tooltip discrepancy for a king with 12 stewardship married to a wife with 9 stewardship under gavelkind succession:
- Rank Base Demesne: 3*1 = 3, displayed as +3
- Stewardship Bonus: 0.15 * (12 + 0.5*9) = 2.4, displayed as +2
- Gavelkind: 30% * 5.4 = 1.6, displayed as +1
- Total: 3 + 2.4 + 1.6 = 7, displayed as +7 and not +6
Wrong settlement type
Characters get a 75% penalty to income and levies in demesne settlements that do not match their government type. These settlements should generally be given to a vassal of the correct type or to a courtier (who will automatically take on the correct type).
- Tribal rulers can only hold tribes without penalty
- Feudal rulers can hold all castles + tribes of their culture without penalty
Patricians can hold all cities and castles + tribes of their culture without penalty
Iqta rulers can hold all castles and mosques + tribes of their culture without penalty, and gain extra piety if they hold mosques.
Nomads cannot hold any settlement without penalty except their nomadic capital.
Monastic Feudal rulers may also hold temples and castles + tribes of their culture without penalty.- Imperial rulers can hold castles and cities + tribes of their culture without penalty
Conversion of tribes in demesne
Rulers who already have advanced government (i.e. not nomadic/tribal) can convert tribes in demesne counties which share their religion. This also requires the tribe to have a Stone Hillfort built. Once the Stone Hillfort is built, right-click on the tribe to convert it. Depending on the number of empty holding slots in the county (minimum two slots), additional free holdings may be added to the ruler's demesne.
This method of converting tribes is more critical when playing as a feudal unreformed pagan.
Other considerations
- If playing as a Muslim Caliph or a
reformer of a pagan faith with the Temporal leadership type, consider holding a temple in one of the denomination's holy sites to increase moral authority. However, note that unless you are a Muslim or a reformed Bön ruler using the Monastic Feudal government, being a religious head does not prevent you from suffering wrong government penalties for directly holding the holy site temple. - If aiming to change religion, consider holding a county of the relevant faith's holy sites for the option of secret conversion. In particular for Abrahamic faiths, consider personally holding the county of Jerusalem. Another way of secret conversion is via a demesne county's religion.
- Holding counties which are considered important on the Silk Road can boost your income as you build and upgrade trade posts.