This book is the first ever monograph on the family of royal converts from Adiabene including the broader perspective of the cultural and political environment of Hellenistic and Parthian Adiabene. It collects, arranges, and discusses all available sources on the topic. The study consists of three parts. The first part is devoted to the longest ancient account on the Adiabene royalty from all ancient literature - Josephus, Ant. 20:17-96 ("the Adiabene Narrative"). It examines the Adiabene narrative as Josephus's conscious literary product with all its rhetorical features and ideological agendas. The second part deals with other sources about the family of royal converts from Adiabene. One chapter is devoted to the Rabbinic traditions about Queen Helena and King Munbaz, another one discusses all Jewish and non-Jewish literary sources that refer to the resting place of Queen Helena and to the palaces of the Adiabene royalty in Jerusalem. Furthermore, it provides an updated discussion of relevant archaeological sites in Jerusalem (Le Tombeau des Rois and the Givati Parking Lot). The third part presents the cultural and political environment of Adiabene from the third century BCE to the third century CE. It discusses all available kinds of sources: geographical and ethnographical texts, archaeological sites, epigraphic and numismatic material, as well as onomastic evidence. One chapter goes on to give a basic chronology of the Adiabene royalty in the Hellenistic and Parthian periods, and the last chapter presents the political environment of Adiabene and Judaea in the context of the international relations between Rome and Parthia in the first century CE.