Why did Egyptian cults, especially those dedicated to the goddess Isis and god Sarapis, spread so successfully across the ancient Mediterranean after the death of Alexander the Great? How are we limited by the established methodological apparatus of historiography and which innovative methods from other disciplines can overcome these limits? In this book, Tomas Glomb shows that while the interplay of different factors such as the economy, climate, and politics created favorable conditions for the early spread of the Isiac cults, the use of innovative quantitative methods can shed new light and help disentangle the complex interplay of individual factors. Using a combination of geospatial modeling, mathematical modeling, and network analysis, Glomb determines that, at least in the regions of the Hellenistic Aegean and western Asia Minor, the political channels created by the Ptolemaic dynasty were a dominant force in the local spread of the Isiac cults. An important contribution to the historiography of the ancient Mediterranean, this book answers the specific question of "how it happened" as well as, "how can we answer it beyond the limits of the established methodological apparatus in historiography."