May 21, 1382: The "Earthquake Synod" in London (so named because a temblor interrupted the proceedings), led by Archbishop Courtenay, condemns as heretical 24 theses from the writings of John Wycliffe. Wycliffe later claimed that God sent the earthquake "because the friars had put heresy upon Christ. The earth trembled as it did when Christ was damned to bodily death".

May 21, 1527: Anabaptist minister Michael Sattler, a former Benedictine monk who left the monastery and married after reading Paul's letters, is tortured and killed in Rottenburg, Germany. His wife was drowned eight days later.

May 21, 1780: English Quaker and social reformer Elizabeth Fry is born in Norwich, England. Though involved in reforms from education to poverty, her greatest burden was to improve prison life.

May 22, 1789: The first American Presbyterian General Assembly convenes in Philadelphia.

May 23, 1430: French mystic and military hero Joan of Arc is captured by the Burgundians. They sold her to English, who tried her for sorcery and heresy.

May 23, 1533: Thomas Cranmer, archbishop of Canterbury, declares King Henry VIII's marriage to Catherine of Aragon null and void: a key moment in the English Reformation.

May 23, 1618: Bohemian Protestant rebels storm the castle of Catholic Hapsburg king Ferdinand II and throw his governors out the window (and into a pile of manure). This act touched off Europe's Thirty Years War, which ended in 1648 by the Treaty of Westphalia.

May 24, 1089 (traditional date): Archbishop of Canterbury, scholar, and church reformer Lanfranc dies. Known primarily for his development of the doctrine of transubstantiation, in which the eucharistic bread and wine become Christ's body and blood, he also educated brilliant scholar Anselm and future pope Alexander II.

May 24, 1689: Parliament passes England's Toleration Act, granting freedom of worship to Dissenters (non-Anglican Protestants). but not to Catholics and atheists.

May 24, 1854: Presbyterians found the first black college in the United States: Pennsylvania's Lincoln University.

May 25, 1535: After holding Munster under siege for over a year, the army of the city's Roman Catholic bishop breaks in, capturing and killing the radical Anabaptists who had taken control. The Anabaptists had acted on the prophecy of Melchoir Hoffman (later modified by Jan Matthys) that Christ would soon return, and only Christians in Munster would survive. During the siege, Matthys and his followers became increasingly despotic and maniacal, enjoying excesses while the people starved and introducing wild innovations such as polygamy (see issue 61: The End of the World).

May 26, 1232: Pope Gregory IX sends the first Inquisition team to Aragon, Spain.

May 26, 1647: Massachusetts enacts a law forbidding any Jesuit or Roman Catholic priest from entering Puritan jurisdictions. Second-time offenders could face execution.

May 26, 1700: Count Nicolaus Ludwig von Zinzendorf, founder of the Moravian church and a pioneer of ecumenism and mission work, is born in Dresden, Germany.