May be formed by: Austria-Hungary
The Danubian Federation (DNB) is a special case, as it cannot simply be formed-- it is an attempt by Austria-Hungary to elevate many of the other Danubian cultures (in this case the Czechs, Slovaks, Slovenes, Croatians, Romanians and Poles) to the same level of equality as the Hungarians... in effect, trying to get them to buy into a willing union and convincing them at the same time that they won't be utterly dominated by the Germans. This is a rough attempt at simulating what Archduke Ferdinand had envisioned as the United States of Greater Austria, and which he might have done had he not been assassinated.
The first step in formation is enacting the Propose the Danubian Federation decision, requiring:
- owns both Vienna and Budapest
- owns any core province of Bohemia, Slovakia, Slovenia, Croatia, Romania or Poland
- Hungary does not exist
- Austria-Hungary is at peace and is a greater power
- Revolution & Counterrevolution
- Social Science
- is a democracy or HMS government
- has a liberal or socialist ruling party
- average militancy is less than 4 and no provinces are rebel-controlled
Once that decision has been taken, the proposal will be taken to each of the cultures of which Austria-Hungary currently owns cores-- beginning with the Hungarians. With each culture, they will come back with one of three responses:
1) Full Agreement -- they endorse the federation. When it forms, their culture will be added as accepted (if it isn't already) and the new country will gain cores on their lands (if they aren't present there already).
2) Partial Agreement -- they will agree to the federation, but only if they are released as a vassal. Their culture will be added as accepted (if it isn't already), but after the Danubian Federation forms they will automatically be released as promised (and the DNB will receive relations and influence). Austria-Hungary can ignore this and still proceed, but then it will be treated the same as a refusal.
3) Refusal -- should the process of federation not be halted right there, forming it will result in their culture being removed as accepted (if it's currently accepted), and all cores on their territory lost (for Hungary, this is only their cores which are not also cores of the other cultures). They will also get a rebellion event adding both +6 consciousness and militancy to their POPs and the "Nationalist Agitation" modifier to their cores for 3 years.
Once all component cultures have had their response event fire, and assuming the federation process has not been halted en route, the Form the Danubian Federation event may be enacted, requiring:
- Austria-Hungary still owns Vienna and Budapest
- is at peace
- is a democracy or HMS government
- average militancy is less than 4 and no provinces are rebel-held
This will turn Austria-Hungary into the Danubian Federation, add +25 Prestige, and replace all Austria-Hungary cores with DNB cores. It also changes the national value to Equality and adds the "Protected" Minority Rights reform as well as the "Two Per State" Upper House reform.
- As you can see, should the Hungarians and any other cultures not accept the federation, it's probably not best to proceed. You could potentially end up with a Danubian Federation that has less cores and accepted cultures than Austria-Hungary. It will be up to you to decide whether it's worthwhile-- once a response event has fired, there's no way to change that culture's mind. It is possible, however, to add some accepted cultures after the fact: the DNB has access to the same "Embrace Culture" decisions that Austria-Hungary has, allowing them to eventually add Czech, Slovene, Croat and Polish accepted cultures even if those cultures refused.
- The best way to heighten the chance of a culture accepted is to make sure militancy is low. As soon as the average militancy of a state with their cores is 3+, the chance of refusing starts to go up. If it's less than 2, the chance of agreeing goes up-- as does having their culture as accepted if they're not Hungarians (meaning Austria-Hungary has already taken some of the "Embrace Culture" decisions. Romanians always have a greater chance of refusing if Romania already exists, as do the Poles if Poland exists. All cultures are otherwise inclined to agree (except for the Poles, who always lean towards either partial agreement or refusal). That said, forming the DNB is a gamble, with huge potential rewards should every culture choose to agree.
- If Hungary ever separates (meaning it exists and is not a vassal), a breakup event will fire where the Danubian Federation must decide whether to become Austria once more (losing all accepted cultures and returning to base Austrian cores) and all vassals and component countries being released. If the Danubian Federation refuses to break up, then it loses all accepted cores anyhow and immediately starts a civil war to retake Hungary. All existing vassals will decide whether to support the federation or separate by declaring an independence war. All non-existing component countries will automatically separate and join in the civil war.
- Similarly, if the Danubian Federation ever becomes totalitarian (meaning it is not either a democracy, HMS government or Prussian Constitutionalism) and either average militancy rises above 4 or more than 25% of the country becomes rebel-controlled, the same breakup event is fired as above.