Huldrych Zwingli took up the post of people's priest at the Grossmunster in 1519 and announced that he would preach straight through the gospel of Matthew rather than follow the prescribed readings, which told his hearers immediately what kind of authority he intended to appeal to. The break became public in 1522, when a printer and his workmen ate sausage during Lent and Zwingli defended them on the ground that scripture nowhere commands the fast.
What happened next set the pattern for Reformed Christianity. Rather than appeal to a bishop, Zwingli asked the city council to hold a public disputation, and in 1523 it did so twice, ruling that preaching in Zurich should be grounded in scripture alone. The council, a civil body, had adjudicated a theological question, and it then implemented the result: images were removed from the churches in 1524, and in 1525 the mass was replaced by a plain memorial supper celebrated four times a year at a wooden table, with the organs silenced and congregational singing set aside despite Zwingli's own considerable musicianship.
He also broke with Luther. For Zwingli the words this is my body are figurative and the supper is a remembrance and a pledge; for Luther the body is genuinely present. The two met at Marburg in 1529, agreed on fourteen points and failed on that one, and Protestantism has been divided along the line ever since. Zwingli was killed in 1531 at Kappel, serving as chaplain with the Zurich forces in a war between the Swiss cantons over religion.