The Persian Empire (539-330 BCE) represented a new political order in world history. At its height, it united a territory stretching from present-day India to Libya. It was three times as large and twice as long-lived as the previously most successful polity (Assyria), and it would take 2,000 years before significantly larger empires emerged in early modern Eurasia. <br/><br/>What explains Persia’s success? This question eludes scholarship due to a lack of evidence and a lack of engagement. Since this Empire unified for the first time in history millions of people under its rule – a condition that became a recurring experience of humanity – understanding Persia’s success transcends its intrinsic relevance to the period in question. <br/><br/>The principal reason why an effective engagement with this question is presently impossible is the lack of data. The PERSIA AND BABYLONIA project presents a substantial new data set that allows us, for the first time, to contextualize the emergence of the Persian Empire as a complex social process, shifting away from understandings of the Empire as a one-dimensional, state-initiated construct. This data derives from cuneiform textual sources that were produced in Persia’s most important periphery – Babylonia. A key analytical device in our work will be to compare Persian responses to those of the Assyrians, who were unable to establish control of Babylonia a century earlier. By combining a long-term with a deeply contextualized perspective, we will be able to draw out the distinctive efficiency of Persian rule, within the long history of this particular region. In addition to making a significant step towards understanding the emergence of Ancient Persia, we will develop a much-needed research tool for historians of empire and society in the ancient world.