Answer:
A dynasty describes a ruling family who succeeded in guaranteeing a continuous occupation of the highest dignity of their country over a long period of time through power, economic and marriage politics, diplomacy, and ultimately a successful succession.
The main advantage that a dynasty can entail as a form of government is the predictability of the governments that they entail, since for better or for worse the policies they carry out tend to be continuous, marking a certainty in political and economic terms for the inhabitants of the place they rule.