This publication in two volumes represents the new standard reference work on the coinage of the Roman Emperor Trajan (98–117). In a systematic catalogue, based on 24,000 individual entries, it illustrates with unprecendented precision all the types and variants of Trajan’s Imperial coins. What is particularly worthy of attention is the systemisation of the manifold busts and depictions of the Emperor used on the coins, as well as the relative and absolute chronology of the minting – in particular the reconstruction of the minting sequence for the especially problematic period of the Fifth Consulate (103–111). For this period a new typological analysis of the portraiture was carried out, which is discussed in the context of the development of the three-dimensional Imperial portrait. As well as the catalogue, which offers extensive material evidence and data on the relative frequency of the individual types and variants, the book contains compact minting tables for easy orientation as well as an introduction covering relevant historical, financial history, numismatic and doxographic aspects. An extensive commentary section explains each order. Multiple indices and concordances for existing reference works, as well as a comprehensive collection of 164 plates combine to make this the indispensable tool of the future for work in this field. Published with support from the Austrian Science Fund (FWF).