Tribal Vassals never become Feudal?

[Foamybeard]

For some reason, my tribal vassals never seem to adopt Feudalism. The same tribal Saxon provinces conquered by Charlemagne are just that - Tribal, despite it almost being the 10th century. I remember that tribal vassals used to be able to become Feudal, when they had a Feudal liege - Why was that option removed?

 

[Recognizable]

They need to have a capital holding that is a castle or Stone hillfort tribe then they can go feudal

 

[Foamybeard]

I've upgraded one to Stone hillfort already. I'm just surprised that they seem to not upgrade to Feudal, being content with being a tribal.

 

[reshogu]

I've upgraded one to Stone hillfort already. I'm just surprised that they seem to not upgrade to Feudal, being content with being a tribal.

What religion are these tribals? If they are non-reformed religion such as norse pagan they will prefer tribalism while reformed prefers feudal

 

[Foamybeard]

Chanceldonian. I managed to convert them all.