Final answer:
Pope Gregory I utilized his authority and wealth to expand the Church's influence through diplomacy and missionary work. Later popes continued to assert authority, leading to conflicts like the investiture controversy, which demonstrated the pope's influence over secular rulers. Despite this, the Church dealt with internal corruption, highlighting the complexity of the papal role.
Step-by-step explanation:
Pope Gregory I, also known as Gregory the Great, used his authority and wealth to advance the interests and independence of the papacy. His authority extended not from military might but from diplomatic savvy and religious prestige.
Pope Gregory played off different Germanic kings against one another, while using his spiritual authority to gain their trust. He also sent missionaries to spread Christianity into the semi-barbaric lands, a move that was both a religious endeavor and a pragmatic effort to expand the Church's influence.
The later Pope Gregory VII continued this trend by exerting papal authority over the appointment of church officials, leading to conflicts like the investiture controversy with Holy Roman Emperor Henry IV. Gregory VII's eventual excommunication of Henry IV demonstrated the pope's ability to challenge secular authority directly.
Additionally, the assertion of papal authority by citing documents like the Donation of Constantine, despite their dubious authenticity, was a common practice by popes to justify their political clout.
However, corruption within the Church, such as simony and nepotism, showed that the spiritual leaders, including the popes, often engaged in worldly concerns as much as they did in spiritual guidance. Efforts to address this corruption were seen in the actions of reformers and were further emphasized during the Protestant Reformation, led by Martin Luther. The Church's attempt at internal reform contrasted with its lavish lifestyle, as it faced criticisms for greed and abuse of power.