CORPUS REFORMATORUM. — Since the 19th century this title has been used to designate a monumental collection of the works of the writers of the Reformation. Still in the course of publication, it also gathers confessions of faith and doctrinal points possessing a certain authority. These religious writings, intended by their authors as rules of faith and teaching and to ensure that the faithful might have a right understanding of God and worthily invoke Him, for the unity of the Church and to curb the audacity of ever inventing new dogmas, were so numerous that by 1560 the need arose to gather them into particular collections, about a dozen in number, which generally took their name from the Protestant region in which they were compiled.
The first collection in chronological order was compiled by Philip Melanchthon, Luther’s theological expert, in 1560, and is therefore called the *Corpus Philippicum*; it was first presented as a private collection and then imposed, by order of certain heads of state, upon all Protestant regions. Almost all the other collections that followed until 1580, namely the *Corpus Hamburgicum* (1560), the *Corpus doctrinae urbis Brunswici* (1563), the *Corpus Pomeranicum* (1566), the *Corpus Prutenicum* (1567), the *Corpus Turingicum* (1570), the *Corpus Bruneburgicum* (1572), the *Corpus Norinbergense* (1573), the *Corpus Willeminum* (1575) and the *Corpus Iulianum* (1576), were compiled precisely to oppose the imposition of Melanchthonian texts. These collections, however, lost their importance when, on 25 June 1580, solemnly proclaimed at Dresden with a prefatory letter signed by 49 princes and 35 cities, the *Liber Concordiae* or simply *Concordia* appeared, with the aim of reviving doctrinal agreement and thus the union among the various dissenting regions, but which instead became the cause and origin of new and more bitter controversies. A few years later, in 1626, a final collection was compiled in Hesse, the *Corpus Hassiacum*, which, however, was not included in the *Corpus Reformatorum*.