A review of the manuscript and imprint tradition proves the importance of Beatus Rhenanus' editions. It also explains the continuing controversy over the manuscript tradition. Sixteen of the imprints preceding Rhenanus' May 1519 work have been examined and the more important collated. Rhenanus' four editions of May and August 1519, of 1533, and of 1544 are described and analyzed; in the first three cases the author had access to Rhenanus' own amply antated copies. This rich and original documentation for Rhenanus' understanding of Tacitus allows the sources and progress of his editing to be detailed and furnishes valuable evidence for his interpretation of difficult passages of the Germania. Rhenanus' successful effort is compared with current contributions. Eight illustrations and the collations of important early imprints accompany the text.