After the diligent work of P. de Jonge, who wrote commentaries on books 14 -18 from the 1930s till the 1980s, J. den Boeft, D. den Hengst, H.C. Teitler and, starting 1991, J.W. Drijvers have steadily worked on the commentaries to the remaining books 19 - 31 of Ammianus Marcellinus' Res Gestae. Their collaborative work has received much praise in the international scholarly world. With the publication of the Philological and Historical Commentary on Ammianus Marcellinus volume XXXI, this series has been completed. The entire set is now available in print, containing 18 commentary volumes.