all of the Targaryen kings starting with Aegon I himself styled themselves as "King of the Andals, the Rhoynar, and the First Men" and "Lord of the Seven Kingdoms" - despite the fact that Dorne remained independent. Aegon I had declared himself king of all of Westeros just before his army even landed on the continent, Dorne included. While Dorne had been able to resist his armies and dragons through guerrilla warfare, Aegon himself never acknowledged that this was a permanent state of affairs. Aegon and all of his heirs considered themselves the de jure kings of the Rhoynar and of Dorne, even if they had no de facto control over it (comparable to how medieval English kings would at times hold titles of lordship over "Wales", "Ireland", and "France", despite not controlling all or even most of these territories).