Any advantage to staying petty king?

[Drachenfire]

So Im still newish to CK3, and love it.

Question about an observation.

In my current game start 1204, the English empire exploded in an succession war and the English lords in Ireland became independent. Once mere dukes in the Kingdom of England, the de Lacy family is now petty kings of Ulster. within a generation, they managed to conquer 98% of Ireland and make half of it English culture.

But they don't seem to be in any rush to form the Kingdom of Ireland.

The dukes of Brittany also do not seem to be in any hurry to become King of Brittany.

For myself, I started as a Prince of Gwynedd and formed Kingdom of Wales pretty quickly.

Is there any .... advantage? to staying independent ducal tier?

[ste]

It cost money they might not want to spend just yet, but there is no advantage to staying a duke

[BrowneHawk]

Only if you like being petty.

[Othobrithol]

Only thing I can think of is that it is no longer possible (unlike in CK2) to create a title equal to your overlord. So if I'm a duke/petty king my vassals can't make ducal titles and suddenly get mad at me for controlling some of their de jure territory. I seriously doubt the AI is that nuanced.

[capercaillie]

being a duke is actually pretty strong under a liege, you can have unlimited duchies compared to being king, which can only have two before the negatives start to appear.

[Drachenfire]

Im really enjoying playing with "prince" title. Kinda wish i could keep that for kingship tier too.

[LordDeed]

The benefit is unlimited duchies (And therefore unlimited duchy buildings), but that also means a lack of vassal limit. You need to choose which is more important too you, are you going to conquer a couple of smallish kingdoms at which point petty king, or are you going for paint the map as fast as you can so king to emperor.

[Othobrithol]

A "Duke(s) of Everywhere" strategy only works if you can, for certain, hold off partition.