During this period, Christianity began to play a more influential role in political affairs. Christian leaders became significant advisors to emperors and kings and were often involved in policy-making. Additionally, the Church began to administer large amounts of land and wealth, which further added to its political influence.
In Western Europe, the fusion of political power and religious authority continued to strengthen during the Middle Ages. The Pope, as the head of the Catholic Church, held significant influence over political and social developments, and often played a role in settling disputes between different factions.
Moreover, the close ties between the Church and the state led to the emergence of theocracy, a system in which religious leaders are also political leaders, as was the case with many of the Holy Roman Emperors and French kings during the Middle Ages.
Therefore, Christianity became a political power in Western Europe during the late 4th and 5th centuries, gaining influence and involvement in political affairs, land administration, and policy-making, while also contributing to the emergence of theocracy and close connections between the Church and the state.