The first 84 volumes of the Tractatus Lutherani were bought at Sotheby’s in 1818. They had been collected and put into chronological order by the schoolmaster and librarian Johannes Gottlob May (1754–1821), who in turn had acquired collections from Matthias Jacob Adam Steiner (1740–1796) and Georg Wilhelm Zapf (1747–1810).

The Tractatus Lutherani are a collection of 538 volumes. Those numbered 1-126 consist of two series, each arranged chronologically: 84 volumes containing c. 1,670 Latin and German tracts by the German Reformers, 1518-50, including 640 by Luther, and a further collection of tracts ranging in date from 1498-1629. To these two series have been added (volumes numbered 127-538) works, mainly of 16th century, but also some of the 17th-19th centuries, including editions of Luther's works.