Final answer:
The term describing the idea that a monarch's power comes from God and not from his subjects' consent is the Divine Right of Kings. This doctrine established that the king is not accountable to earthly powers but only to God, legitimizing absolute monarchical rule.
Step-by-step explanation:
The term that describes the idea that a king's power is granted to him by God, and not by the consent of his subjects, is known as the Divine Right of Kings. This concept holds that the monarch is above any earthly authority and that they derive their right to govern directly from the will of God. As such, a king's legitimacy is not dependent on the approval of the people or any earthly institution, but solely on divine sanction. According to this belief, only God can judge an unjust king, and any action against the monarch is seen as being against God's will.
The Divine Right of Kings was particularly influential in establishing the absolute power of monarchs who considered themselves subordinate to no one, both in religious and secular matters. Such rulers created laws, conducted foreign policy, dispensed justice, and levied taxes entirely under their authority, often taking steps to reduce the power of the nobility and other potential threats to maintain their control. Over time, the divine right has largely been replaced by other concepts of governance, but it played a significant role in the development of political systems in Europe and around the world.