This document provides background information on key figures and events of the Protestant Reformation, including Martin Luther, John Calvin, Ulrich Zwingli, and Henry VIII. It discusses Luther's 95 Theses and nailing them to the church door in 1517, as well as his opposition to the selling of indulgences by the Catholic Church. It also summarizes the differences between Luther's and Calvin's views on topics like the Lord's Supper and the relationship between church and state.