In the late 1740s the Moravian Church underwent a profound crisis, viewed afterwards as a sifting by Satan (cf. Luke xxii.31). In February 1749 Count Zinzendorf issued a letter of reprimand and removed his twenty-year-old son Christian Renatus from effective leadership of the Moravians’ model community, Herrnhaag. The crisis proved to be a turning point, its ultimate consequence – after Zinzendorf's death – abandonment of his distinctive theology and spirituality and reinvention of Moravianism as part of mainstream Protestantantism, distinguished by little more than distinctive liturgical customs and an emphasis on community life. But Zinzendorf and his contemporaries were deliberately vague as to the Sifting's content, and his successors purged the otherwise voluminous Moravian archives of most of the evidence for what precisely occurred. Nineteenth-century Moravians extended the ‘Sifting Time’ to cover most of the 1740s and anything that now seemed unusual or unorthodox. German Moravians sought to protect Zinzendorf's memory by separating him from his own theology, British and American Moravians to separate him from an invented ‘true’ Moravianism. Though scholars have increasingly pointed to the falsity or inadequacy of previous interpretations, the riddle has remained: what happened and why, and how should it be interpreted? Paul Peucker answers those questions as definitively as the sources will allow. The Sifting was not a period, but a moment when erotic bridal mysticism culminated in some losing sight of the distinction between earth and heaven. They believed that they experienced union with Christ, rendering holy communion and studying Scripture unnecessary. Metaphors of union with the Bridegroom, such as kissing and embracing, were acted out between men and by men with women. On 6 December 1748 Christian Renatus declared the single brethren to be sisters (brides of Christ) and absolved from future sins. Peucker presents isolated but compelling evidence for religiously-motivated extra-marital sexual activity between men and women. It was this that prompted Zinzendorf's intervention. Homo-erotic description of the union between single brethren and Christ, and of its celebration between single brethren, makes homosexual activity also likely: isolated comments suggest that it occurred, but this remains unproven. Much that has hitherto been regarded as part of the Sifting Time was not. During it, ‘blood and wounds’ spirituality was neglected: returning to it was the remedy. By 1748 the controversial hymns of 1745 were similarly no longer in vogue. The Sifting, Peucker argues, was the logical – though unintended – consequence of Zinzendorf's marital theology. After his death his Church's new leaders moved swiftly to distance it from radical religion. His son-in-law Johannes von Watteville (regarded by some as ultimately responsible for the catastrophe) was prevented from assuming sole leadership (the Church took on Zinzendorf's debts in return for his family ceding power); ordination of women as presbyters was abolished; access to the archives was restricted. Over time women's roles were greatly reduced, there was a gradual but determined departure from Zinzendorf's theology, new publications presented a revised image of him, and archival material that would contradict this was destroyed. All previous accounts of the Moravian ‘Sifting Time’ stand corrected by this magisterial survey.