Coronation is a mechanic affecting Catholic Kings and Emperors. It requires the 
Holy Fury DLC.
Overview
Succeeding to the throne of a Catholic Kingdom or Empire is not just a simple matter of gaining the title itself. The new ruler needs to organize a Coronation Ceremony and be recognized as legitimate by a notable clerical member of the Catholic Church.
If a Catholic ruler fails to be officially crowned, he will see his popularity slowly fade away each year, as his vassals grow more and more restless under what they perceive as an illegitimate King.
Under the HRE's Princely elective succession, the Emperor can only sway voters if they have been crowned.
Requirements
Rulers are expected to be crowned if:
- the Holy Fury DLC is active
- King+
- Catholic or Fraticelli
- Has any feudal government
- Not a viceroy
However, these rulers may only use the "Organize a Coronation Ceremony" decision when:
- Not
- Not
- Either at peace, or still uncrowned after 30 years of rule as an adult
- Either not
, or has Free Investiture, or is king-tier - Either an adult or 11+, assertive (
, 
, 
, or 
), and liked by regent (opinion at least 0) - Is NOT inaccessible
- Is NOT otherwise occupied
- Has NOT recently attempted to organize a coronation
- Is NOT currently waging a war as part of a deal to be crowned by the Pope
- Either:
- A Pope exists and is available
- A vassal bishop is available (for emperors, this option also requires Free Investiture)
Mechanics
Coronation is divided into two phases: preparation and ceremony. During the preparation, the ruler will decide whom he wishes to be crowned by, he will meet the Church’s demands, and invest money to organize the ceremony. In the second phase, the ruler will host the ceremony itself, interacting with guests and ultimately receiving his crown.
When organizing a ceremony, a Catholic King can choose between three possible options when it comes to officiant priests:
- A low-status theocratic vassal within his realm;
- A powerful theocratic vassal within his realm (such as a Cardinal, Antipope or Prince-Bishop);
- The Pope himself
Catholic Emperors who have the Papal Investiture law are limited to only the Pope. Similarly, rulers controlling an antipope cannot ask the Pope to officiate a ceremony.
While being crowned by a local Bishop is a lot less prestigious, it is also much cheaper, as higher-ranking members of the Church are more likely to make outlandish requests, especially if they dislike the ruler requesting them to officiate his coronation.
Requests
Requests may vary a lot, especially when it comes to the Pope: the Holy Father might ask you to change your realm’s Investiture laws, wage war against an Excommunicated ruler on behalf of the Papacy, or to restore some of the Central Italian provinces to the Holy See (specifically, counties which are de jure part of the Papal States). If vassalized, the Pope might ask for independence as a request. Be sure to be in good relations with the Pope before asking for a coronation if you wish to receive a more tolerable request. If the Pope is vassalized, set the realm's Investiture Laws to "Free" so that the Pope can request for a law change rather than independence (and you can then choose another clerical vassal if you don't wish to fulfil the request offered).
Budget
Once the demands of your chosen priest have been met, you will be able to select a budget for your ceremony which will determine the kind of coronation you will receive, the kind of flavor events tied to it and the number of guests participating in it.
- An extravagant coronation is a prestigious event to which all your vassals, courtiers and even neighboring Christian rulers are invited. Positive events are more likely, and you will get the "Extravagant Coronation" modifier for 20 years (+10 vassal opinion, +0.25 monthly prestige)
- A secluded coronation is a private feast to which only your Council will have access.
Completion
Once the ceremony has been concluded, your character will receive a specific trait tied to the priest that crowned him, as well as retain any additional perks granted by the flavor events experienced during the feast leading up to the coronation.
Until coronation, you do not have a high-tier headgear (crown) yet. Just after coronation, you will get special heritable headgear.
Self-Coronation
In order to crown oneself, your character must:
- Be an emperor
- Be at least 16 years old
- Have spent the highest possible sum on the coronation
- Be about to be crowned by the Catholic pope specifically
- Be any of:
,
,- a
Satanist, or - with imperial administration.