https://en.wikipedia.org/wiki/Heinrich_Bullinger

Biography: The Reverend and most learned Heinrich Bullinger, born at Bremgarten in Helvetian Aargau on 18 July 1504, was providentially drawn from Rome’s schoolmen to the evangelical truth, being converted through diligent search of the Fathers and Luther’s writings, whereupon he cast off monastic vows and embraced the pure doctrine of grace. After the martyr-fall of Huldrych Zwingli, the city of Zürich chose Bullinger, then scarce twenty-seven, to be antistes and preacher in the Grossmünster; for nearly forty-five years he thundered Christ from that pulpit and governed the churches with equal parts charity and discipline. A tireless penman, he issued the Decades—fifty homiletical common-places that became a household theology in England, the Low Countries, and beyond—and poured forth some 12,000 letters to succour scattered saints. Standing Athanasius-like for the truth, he co-framed the First and Second Helvetic Confessions, forged with Calvin the Consensus Tigurinus, and expounded the covenant of grace, uniting Swiss and Genevan brethren in a spiritual presence of Christ at the Supper. Having preached, by sober reckoning, almost twenty-eight thousand sermons, he surrendered his spirit on 17 September 1575, leaving to the Reformed churches a treasury of doctrine, a pattern of pastoral constancy, and an enduring testimony that “the Word of our God shall stand for ever.”

Biography: The Reverend and most learned Heinrich Bullinger, born at Bremgarten in Helvetian Aargau on 18 July 1504, was providentially drawn from Rome’s schoolmen to the evangelical truth, being converted through diligent search of the Fathers and Luther’s writings, whereupon he cast off monastic vows and embraced the pure doctrine of grace. After the martyr-fall of Huldrych Zwingli, the city of Zürich chose Bullinger, then scarce twenty-seven, to be antistes and preacher in the Grossmünster; for nearly forty-five years he thundered Christ from that pulpit and governed the churches with equal parts charity and discipline. A tireless penman, he issued the Decades—fifty homiletical common-places that became a household theology in England, the Low Countries, and beyond—and poured forth some 12,000 letters to succour scattered saints. Standing Athanasius-like for the truth, he co-framed the First and Second Helvetic Confessions, forged with Calvin the Consensus Tigurinus, and expounded the covenant of grace, uniting Swiss and Genevan brethren in a spiritual presence of Christ at the Supper. Having preached, by sober reckoning, almost twenty-eight thousand sermons, he surrendered his spirit on 17 September 1575, leaving to the Reformed churches a treasury of doctrine, a pattern of pastoral constancy, and an enduring testimony that “the Word of our God shall stand for ever.”

Systematical Theologies:

Compendium Religionis Christianae