Final answer:
The papacy held peak authority in the Middle Ages, serving as a religious and political power. Challenges like the Avignon papacy and the reformation led to calls for church reform. By the 16th century, the Church had regained strength, focusing on its spiritual mission and ecclesiastical presence.
Step-by-step explanation:
The papacy reached its zenith of influence and power during the Middle Ages, performing both spiritual and political leadership roles. Not only did the popes claim religious authority over the Catholic Church, they also ruled as temporal kings, wielding immense influence over states and monarchs. For instance, Pope Innocent IV, who served from 1243 to 1254, and his contemporaries commanded armies, forged alliances, and sometimes engaged in warfare much like any other secular ruler.
However, the relationships between the papacy and other rulers were complex. The power dynamics were not always steady, with events such as the Avignon papacy and the Great Western Schism eroding the church's reputation and authority. Martin Luther's reformation was in part a response to the corruption and perceived greed within the church, highlighting the need for spiritual renewal and reform.
Despite the challenges, by the end of the sixteenth century, the Catholic Church re-emerged with a clear mission and purpose. The papacy instituted reforms, encouraged piety and asceticism, and initiated grand architectural campaigns to rebuild Rome's image as a holy city, thus reaffirming its central role in the lives of the faithful.