Becoming a noble family

[Sandermatt]

If I start as a ruler in the byzantine empire that is not a noble family, how do I become one?

[Razorblade]

If no one of your House already has a Noble Family title, they'll gain one when one when they are appointed as a Governor.

If your family does already have a Noble Family title, but you want your own instead of just trying to inherit that one, then you need to create a Cadet Branch via Decision. As that changes your character's House, you'll be granted your own Noble Family title if you're a Governor / once you become a Governor.

[Sandermatt]

Ah, so, basically all the counties are too low rank to be a noble family, but the dukes are.