Zürich’s first evangelical service of the Lord’s Supper occurred in a dramatic fashion during Holy Week 1525. Before the sun rose on Maundy Thursday, Huldrych Zwingli (1484–1531) had a dream sparked by the groundbreaking decision of the Zürich city council earlier in the week to abolish the Mass. The discussion which led to this momentous breakthrough involved an argument with conservative under-secretary Joachim am Grüt over the precise signification of the Eucharist, a dispute which vividly appeared to Zwingli anew as he slept. A counselor appeared in his dream, calling him out of his slothfulness and directing him to the parallel between the Passover and the Lord’s Supper. Zwingli immediately awoke, meticulously examined his Bible, and that morning expounded the passages before the congregation with such might that he persuaded nearly all those present. The ensuing worship over the course of the Easter Triduum drew crowds so numerous, that Zwingli remarked: “such a Passover of Christ was celebrated as I have never yet seen”.
Huldrych Zwingli was born on 1 January 1484 in Wildhaus in the Toggenburg valley region of Switzerland. After schooling in Basel, and then Bern, he arrived at the University of Vienna in 1498, where he completed his Bachelor of Arts. There he became friends with Joachim Vadian (and would have overlapped too with Diebold Schwarz). In 1502, he moved to the University of Basel, where he met Leo Jud and Konrad Pellikan, and proceeded Master of Arts. He was ordained in 1506 and ministered in Glarus, where he taught himself Greek, and read and corresponded with the great Erasmus. In 1516, he moved to the Benedictine Abbey in Einsiedeln as the people’s priest and grew to love the Scriptures, even preaching the truths of the Gospel against indulgences and Marian veneration. His most important ministerial appointment came in 1519, when he became the people’s priest at the Great Minster (Grossmünster) in Zürich.
The next five years witnessed three important manifestations of Zwingli’s growing evangelicalism. First, he established himself as a skillful expositor of the Scriptures. His first sermon on 1 January 1519 (his 36th birthday) began at the first chapter of the Gospel of Matthew and he preached sequentially through books of the Bible. Second, he took a public stance on the evangelical freedom from fasting. During Lent in 1522 there were a dozen men at the house of the printer, Christopher Froschauer. Due to the expensive price of fish, Froschauer asked his wife to purchase some meat, and she returned with two smoked sausages which were cut into pieces and distributed among the twelve (somewhat of a striking parallel to the Last Supper). Although Zwingli refused, everyone else ate the sausages, including the pastors Leo Jud and Laurence Keller. News of this shocked the city, so Zwingli preached a sermon on fasting and defended his friend’s Christian freedom. Just as the “Sausage Affair” was dying down, the third manifestation of Zwingli’s growing evangelicalism occurred that year: he secretly married Anna Reinhard in the spring, and publicly denounced compulsory clerical celibacy in the summer, through his publication, A Friendly Petition and Admonition to the Confederates.
By this time, Zwingli was firmly convinced of the once-for-all sacrifice of Christ at Calvary. He lambasted the supposed sacrifice of the Mass in two publications: An Attack on the Canon of the Mass (1523) and the Commentary about the True and False Religion (1525). These evangelical opinions spread rapidly, and after the city council approved his proposal (excepting the antiphonal recitations) to replace the Mass with an evangelical worship on Tuesday of Holy Week, 1525, he implemented his landmark liturgical reforms during the celebration of Easter only a few days later.
Zwingli’s decision to celebrate the Lord’s Supper on four occasions throughout the year (Easter, Pentecost, Autumn and Christmas) meant the creation of two liturgical orders: a weekly service of the Word, A Form of Prayer … At the Beginning of the Sermon and a seasonal service of the Sacrament, Act and Custom of the Supper. ….
[the rest of this introduction will be in the book, but here is an interesting sample from Zwingli’s Preface in the Act and Custom]
“After being long in error and darkness we rejoice, most beloved brethren, over the right way and the light, which God our heavenly Father has made known to us through His grace. And we have valued it much more highly and received and embraced it with a much greater desire, because the errors were many, harmful and dangerous. But although innumerable errors have occurred until now, to the detriment of faith and love, it seems to us that not the least of them occurred in the abuse of this Supper. Just as the children of Israel reintroduced the Passover lamb in the times of the kings Hezekiah and Josiah, so we by God’s help, as we hope, have reclaimed the Easter Lamb after a long captivity and restored it to its proper use.”
 Huldrych Zwingli, Subsidium sive coronis de eucharistia (Tiguri: Frouscher, 1525), sig. D.iiir: “Ibi ἀπὸ μηχανῆς visus est monitor adesse (ater fuerit an albus, nihil memini, somnium enim narro), qui diceret: Quin ignave respondes ei, quod Exodi 12. scribitur: Est enim Phase, hoc est: transitus domini.”
 Ibid., “Factumque est, ut tribus istis diebus coenae domini Parasceues ac Resurrectionis tantum pascha Christi celebratum sit, quantum ipse nunquam vidi: eorumque numerus, qui ad allia ollasque Aegyptias respectarent opinione longe minor esset.” The Easter Triduum, also known as the Holy or Great Triduum is liturgical shorthand for the period which spans Maundy Thursday, Good Friday, Holy Saturday, and Easter Day.
 29 March; printed on 16 April as Regarding the Choice and Freedom of Foods.
 The reference to ‘Autumn’ may imply the Feast of Felix and Regula, or All Saints’ Day.
 Huldrych Zwingli, Ordnung der christenlichenn Kilchenn zuo Zürich. Zürich, 1525; Huldrych Zwingli, Action oder Bruch des Nachtmals. Zürich, 1525.