Why did monarchs often claim the Devine right of kings?

The divine right of kings or God's mandate is a political doctrine that maintained that a monarch is not subject to any earthly authority because his right to rule is a direct will from God. It suggests that any attempt to dethrone a monarch or to curtail his powers is an act of sacrilege because only God can judge an unjust king. Monarchs claim this divine right so that they can use punishment to demand obedience from the people. They would hold public executions to generate fear and ensure that they have the allegiance of the people.