BigBoss1

I believe it is in between the stormlands and the reach but directly sworn to kings landing.

Well, technically Victarion does have the title of lord. Lord captain of the iron fleet. He should be adressed as lord both because of his station and because of his position regardless of owning actual land. Maybe the iron island don't have princes and Theon deluded himself into thinking he was one. I dont remember if Asha calls herself a princess.

Stannis was direct heir to Robert for a while too Aegon VI at some point wasn't son of a king but was still prince of the blood. Do we know how the iron born dealt with this? Their line descends from the old Greyjoy kings elected at the kingsmoots but i remember Victarion was still a lord even tough he was brother to two kings?

Thats definitely a baratheon thing because the summerhall branch of house targaryen were princes hence prince of summerhall

It seems that the Baratheon dynasty abandoned the Targaryen practice of having every member of the royal family have a princely title. Even distant relatives could still claim to be princes. Why did Robert change that?