Final answer:
The break between Protestantism and the Roman Catholic Church was sealed by several individuals, including Martin Luther and John Calvin, who challenged the authority and practices of the Catholic Church.
Step-by-step explanation:
The break between Protestantism and the Roman Catholic Church was sealed by several individuals and events. Martin Luther, a German monk, started the Protestant Reformation in 1517. He challenged the authority and practices of the Catholic Church, sparking a movement that led to the creation of various Protestant churches. Other influential figures, such as John Calvin in Switzerland and Henry VIII in England, also played a role in distancing themselves from the Roman Catholic Church.