Final answer:
The Roman Catholic Church's wealth and influence were significantly diminished due to the Protestant Reformation, instigated by Martin Luther and others who challenged the Church's authority, leading to the spread of Protestantism throughout Europe.
Step-by-step explanation:
The Roman Catholic Church experienced significant challenges to its authority and consequent financial losses as a result of the Protestant Reformation. This movement, initiated by figures such as Martin Luther and John Calvin, led to the creation of Protestant churches, which drew followers and resources away from the Catholic Church. It began peacefully in some regions but escalated into religious wars elsewhere. As Protestantism spread, especially across northern Europe, the Catholic Church's wealth was depleted—not only due to lost followers but also because of the efforts and resources it spent attempting to combat the rise of Protestantism and the challenges to its religious and political influence.
The internal split caused by the establishment of the Eastern Orthodox Church and the external challenge posed by the Protestant Reformation were both significant in diminishing the Catholic Church's influence. Spain, a staunch defender of Catholicism and the most powerful Catholic empire, expended immense resources to counter the spread of Protestantism but ultimately failed to stem its growth. Luther's accusations against the Church's greed and abuse of power resonated with many across Europe, further weakening the Church's financial and spiritual standing.