John Foxe's De censura, sive excommunicatione ecclesiastica, rectoque eius usu, published in 1551, was the earliest tract to be written by an English Protestant on the subject of ecclesiastical discipline and, as such, deserves a closer examination than it has received to date. Given that continental Protestants and, later on, Puritan apologists alike accepted as axiomatic that the Reformation could only be established on the twin pillars of pure doctrine and right discipline, the appearance at this time, amid a stream of doctrinal polemic, of a tract on discipline, was significant. It indicated that Protestants had become confident enough, after waging war on the claims of the Church of Rome, to regulate the lives of its members, to assert similar claims in the name of Scripture and reformed ‘true religion’. That this tract should appear in Edward VI's reign, and not earlier, was important in this respect, for the effect of the Henrician Reformation had been to render impossible any suggestion that the Church should or could be autonomous in discipline. The psychological climate - as well as the theoretical framework - of the Supremacy persisted throughout Edward's reign, but the fact that the king was a minor gave Protestants a breathing space in which to approach the problem of trying to bring the Church into line with pure, apostolic models. In terms of quantity of published material, doctrine, rather than discipline, was undoubtedly much the more important of the issues discussed; by dealing with discipline a Protestant writer was grasping the nettle, for the subject raised questions about the relative roles of Church and State in the reformation of society and, ultimately, about the structure of the national Church. Foxe's tract was the first attempt to face the question of discipline; that it was the only one, even in Edward vi's reign, showed what a hold the Supremacy had taken. The aim of this article, therefore, is to bring out the significance of Foxe ‘s tract and to explore some of the tensions in mid-Tudor Protestant thought which it reflects. The first part (by Catharine Davies) aims to set it more precisely in its Edwardian context; the second (by Jane Facey) uses it to illuminate the changed emphasis of Foxe's thought on the relationship of Church and State required by the writing of the Acts and Monuments.