So the concept of Dharma is very important in normative (officially sanctioned or canonical / scriptural) Hinduism.
The king ensures the wellbeing and prosperity of all in ruling by the principles of Dharma.
Brahmins are necessary for the rituals that enable the king to maintain the divine power needed to support the kingdom.
The Hindu Dharma thus maintains a social hierarchy in which each class of position has prescribed duties sanctioned by religious authority.