Applying insights from a massive historical research project-Seshat: Global History Databank-this edited volume reveals that there was no single "Axial Age" in human history. Instead, it points to cross-cultural parallels in the co-evolution of egalitarian ideals and constraints on political authority with sociopolitical complexity. The first book-length publication to make use of Seshat's systematic approach to collecting information about the human past, Seshat History of the Axial Age expands the Axial Age debate beyond first-millennium BCE Eurasia. Fourteen chapters survey earlier and later periods as well as developments in regions previously neglected in Axial Age discussions. The conclusion? There was no identifiable Axial Age confined to a few Eurasian hotspots in the last millennium BCE. However, "axiality" as a cluster of traits emerged time and again whenever societies reached a certain threshold of scale and level of complexity. Co-editors Daniel Hoyer and Jenny Reddish paired some of the world's leading historians, archaeologists, and anthropologists with members of the Seshat team. Hoyer, Project Manager with Seshat, is a historian and social scientist specializing in cross-cultural historical analysis. Reddish, Seshat's Lead Editor, is an anthropologist working on the material correlates of cultural systems from societies around the world. She is based at the Complexity Science Hub, Vienna. Seshat: Global History Databank was founded in 2011 to bring together the most current and comprehensive knowledge about human history in one place, collecting what is known about the social and political organization of human societies to track how civilizations have evolved over time. Seshat History of the Axial Age is the first entry in the Seshat Histories series.