Through the incorporation of primary source material and prior scholarship this study looks at the Serapeums, Isiac temples and coinage of Hellenistic Alexandria and Imperial Rome. This study seeks to provide, through close analysis and comparison, a more precise picture of the Isaic ideology of the Greco-Roman governing powers of Egypt. I focus on the capital cities of Alexandria and Rome to analyze the message of Isis to their respective inhabitants. Coinage and popular iconography (such as Isis Pelagia) are incorporated into the overall understanding of Isiac uses as coinage serves as a form of ancient propaganda. The amalgamation of this information provides a clearer picture of Isis as a representation of Egyptian favor and divine validation of kingship over Egypt. Overall, the study found that the ideological manifestations of Isis set forward by the Ptolemies used Isis as a tool of cultural fusion and of positive influence on commerce. After the Ptolemies, the Imperial relationship with Isiac ideological function is made by discussing the actions made by Augutus, Domitan, Hadrian, Antoninus Pius, and Caracalla. As Isis becomes embraced by the Roman empire we see that the Ptolemaic forms of connection to Isis influenced the methods which Roman emperors then paid homage to her. The study finds that through her connection to Egypt, Isiac devotees, Egyptian commerce, and the divine kingship of Egypt during both the Hellenistic and Imperial periods; Isis became an invaluable ideological tool for the governing powers.