This article describes a new method of scholarly investigation developed for studying the history of complex codices united by a common subject-a type of codices now dubbed ‘thematic books,’ as presented in a 2016 publication. The first part describes the fundamental concepts, based on the codicology of complex manuscripts. It takes into consideration the materiality, the content and the structure of the codices, as they are found today, in order to reconstruct the various configurations in which their constitutive units once circulated, and evaluate the relevance of each configuration as a thematic book. In the second part, the method is applied to the category of byzantine anti-Jewish codices. Questions concerning the analysis of individual Production Units are discussed first, followed by questions linked to the relation between the various Production Units in the same codex.