Heinrich Bullinger (18 July 1504 – 17 September 1575) was a Swiss Reformer and theologian, the successor of Huldrych Zwingli as head of the Church of Zürich and a pastor at the Grossmünster. One of the most important leaders of the Swiss Reformation, Bullinger co-authored the Helvetic Confessions and collaborated with John Calvin to work out a Reformed doctrine of the Lord's Supper. Source: Wikipedia (en)