Final answer:
The historian is investigating the medieval European concept of Divine Right of Kings, where monarchs claimed their authority to rule was given by God, affording them absolute power.
Step-by-step explanation:
The historian writing a paper on the idea of Divine Right of Kings in Europe during the Middle Ages is analyzing the belief system that monarchs were appointed by God to rule, which granted them absolute authority over their subjects. This doctrine suggested that kings were not accountable to any earthly authority, such as the will of their people, the aristocracy, or the Church, and that only God had the power to judge them.
Citing historical precedents such as Pope Leo III's coronation of Charlemagne, the historian might discuss how the Church claimed the authority to appoint kings while, in turn, absolute monarchs asserted their right to rule as God's representatives, with complete control over law, foreign policy, justice, and taxation.
Through the divine right, kings aimed to legitimize their rule and weaken the powers of their nobles, who might pose a threat to their sovereignty. However, various events, like the Magna Carta in England, illustrated that the extent of this divine right was not absolute and could be challenged, ultimately shaping the political landscape of Europe and influencing concepts of governance and state authority.