The reign of August i of Saxony (r. 1553–86) saw some of the most intense struggles within German Lutheranism. Nowhere was the contest between the Gnesio-Lutherans (‘true’ Lutherans) and the Philippists (followers of Philip Melanchthon) sharper than at the universities of Wittenberg and Leipzig in the 1560s and 1570s. At a time when the Elector was working hard to secure the hold of his dynasty on the Electoral title that had been confiscated from his Ernestine kinsmen in 1547 and to establish his position as the leading Protestant prince in the Holy Roman Empire, the war between the theologians threatened to become a serious destabilising force. Problems of finance and administration paled in comparison with the unrest that rippled amongst students and townspeople as the scholars and divines screamed invectives at each other and accused each other of precipitating the imminent ruin of society. The precise combination of circumstances at court that led the Elector to instigate a purge of the Philippists at Wittenberg in 1574 is conventionally said to be unknown. Ulrike Ludwig's meticulous and exceptionally well written study offers the first definitive account of this decisive episode in the history of Lutheranism. She identifies three phases in the unfolding drama. First, the publication of the Philippist ‘Wittenberg catechism’ in 1571 unleashed a storm of controversy, in which the Elector intervened by dismissing the Philippists in 1574. The second phase was dominated by the activities of the moderate Orthodox Lutherans who were hired to replace them: they instigated a visitation of the Albertine territories in 1574–5 which focused on the exposure of crypto-Calvinist teachings. Only in the third phase, which began with the appointment of the Tübingen theologian Jakob Andreä as the Elector's theological adviser, did the drive against crypto-Calvinism turn into a wide-ranging reform programme aimed at establishing a new basis for the Electorate's church, schools and universities. Andreä's main role was to establish the theological framework. This he did with the Formula of Concord of 1577, which was published in German translation together with other fundamental doctrinal texts as the Book of Concord in 1580. Alongside the role of Andreä, Ulrike Ludwig emphasises the contribution made by the Elector himself to the reforms. A particular concern seems to have been the desire to ensure that the universities trained loyal and orthodox territorial officials, a mission that was in doubt as the theological disputes added fuel to other discontents to generate worrying levels of student unrest. The subsequent failure of the Elector Christian i (r. 1586–91) to turn Saxony Calvinist is a tribute to the success of his predecessor August i. By 1586 orthodox Lutheranism was too firmly established in Saxon society and in Saxony's administration and educational institutions for the efforts of Christian i to constitute anything more than a brief interlude in a tradition of orthodoxy that endured into the nineteenth century. Ludwig's study illuminates the interaction between politics and religion in an exemplary fashion; it represents a significant contribution to scholarship.