Long-term causes included widespread criticism of the wealth and political power of the Catholic Church.

Practices such as simony (the selling of church offices) and nepotism led to accusations of corruption.

The sale of indulgences—papal grants promising remission from punishment for sins—was a major point of contention.

Christian Humanist scholars like Erasmus advocated for a return to a simpler, more authentic Christianity based on the study of the Bible.

Early critics of the Church, such as John Wycliffe in England and Jan Hus in Bohemia, had challenged papal authority and doctrines before the 16th century.

The invention of the printing press allowed critical ideas to spread quickly and widely, beyond the control of church authorities.

The rise of powerful, centralized nation-states led monarchs to resent the political and economic power of the Pope within their territories.

Many local rulers saw an opportunity to seize Church lands and wealth by breaking with Rome.

A growing sense of national identity in places like Germany contributed to resentment of Italian dominance over the papacy.

The combination of religious, political, and social grievances created a fertile ground for a major religious upheaval.