Ulrich Zwingli was a Swiss Protestant reformer who played a key role in the Reformation during the early 16th century. Born in 1484 in Wildhaus, Switzerland, he became a priest and later the pastor of the Grossmünster in Zurich. Zwingli emphasized the authority of Scripture and sought to reform the church by rejecting practices not grounded in the Bible. Zwingli's teachings focused on the importance of faith and the interpretation of the Bible. He disagreed with the Catholic Church on various issues, including the nature of the Eucharist. His ideas laid the foundation for the development of the Reformed tradition and influenced later reformers like John Calvin.