Newbie Question - Why would I pick Personal Union over Vassal as a subject relation?

[MarkDey]

Hi all! I'm playing as Castille with no DLCs and have a newbie question. I've released Morocco as a Catholic vassal, and will support their conquest of North Africa and eventually integrate them. I'm looking to make Portugal my subject as well, but I'm undecided on the best way to do it.

Assuming I don't get the event that makes them a junior partner under Castille, should I claim their throne and enforce a personal union (one war?), or should I militarily force them to be my vassal (two wars, probably?) I'm leaning towards the latter since that would give a benefit of some income while I wait for them to colonize a bunch of land before I integrate them (100+ years?) I'm not understanding why a personal union would be better in this case, since I don't want to inherit them until they've colonized a lot of the new world alongside my colonists.

 

[Republic of Mercury]

Vassals gain liberty desire based on the strength of all your vassals compared to yours; Juniors in a union only compare their own strength to yours.

If you have the casus beli, you can enforce a union any any country by winning a war. But if you can't get the warscore cost for all of their provinces below 100%, you can't force-vassalise them in a single war.

Those are the main two reasons I can think of, in a nutshell.

 

[bokorthedust]

There's also that you can inherit small to medium sized PUs after the initial 50 years have passed without the PU breaking, saving you the integration cost. Portugal is an example of such a PU, they aren't that big of a nation, and if you are Castile you can even control their expansion before you PU them.

Also, some PUs, like Aragon/Castile or Lithuania/Poland can be inherited for free by way of forming Spain or the Polish-Lithuanian Commonwealth.

 

[MarkDey]

Portugal is an example of such a PU, they aren't that big of a nation, and if you are Castile you can even control their expansion before you PU them.

That's interesting - how could I control their expansion? (I have no DLCs, so I'm not sure if that's a DLC thing.)

 

[st360]

1) You have a chance to eventually instantly annex a PU for free.

2) PUs have different, mostly better subject options than vassals (you can take money from them but cant make them marches, for instance).

3) PUs wont add to the liberty desire of vassals.

4) Unless you have a very rare "force vassalize" casus belli, vassalizing a nation will cost diplo points. PUing a nation is always free (or more precisely, is impossible to do without the casus belli giving that option for free).

5) PUing gives way less agressive expansion (I think, not 100% sure)

 

[holyvigil]

As noted above the most important reason to PU Portugal over vassalizing them is lower liberty desire.

You want Portugal as a long term subject because they have the same culture group as you and will colonize for you.

Over the long term it is tough keeping Portugal's liberty desire down as a vassal because they will naturally get over the cap of loyalty and will become disloyal. As a PU it's easy keeping them loyal.

 

[bokorthedust]

That's interesting - how could I control their expansion? (I have no DLCs, so I'm not sure if that's a DLC thing.)

You ally them and call them into your wars, leaving the AI little opportunity to pursue its own agenda. AI Portugal likes to go into Morocco, and if he grown you can't inherit him because every province the AI has lowers the inheritance chance by -1%, and you need to have a positive chance to freely inherit.

 

[Nostalgium]

Even considering your instant annex worries, they're still present with a vassal. If you have a vassal subject in a Royal Marriage, and the conditions that would normally create a PU are met, they will instead be immediately annexed. Now granted, this is very rare, but it can happen.

 

[MarkDey]

Even considering your instant annex worries, they're still present with a vassal. If you have a vassal subject in a Royal Marriage, and the conditions that would normally create a PU are met, they will instead be immediately annexed. Now granted, this is very rare, but it can happen.

Good to know!

 

[cuendillar]

You don't really want money from Portugal anyway, unless you're really desperate for it. Their ideas gives them faster growing colonies and once you inherit/annex them you'll get their resulting colonial nations (CNs for short). Having multiple CNs in a region also has the advantage of giving more merchants and other bonuses and is impossible to achieve without taking over other colonizers so making sure they can afford to use all their colonists non-stop means you get stronger long-term. You may actually want to subsidize your own and Portugal's CNs to make sure they colonize and maintain decent forces too, if you can afford it.