A lack of source material stifles historical understanding of Late Antiquity, a period whose massive impact is often lost on us. This dynamic also erases many important figures from mainstream historical discussion, none moreso than Khalid ibn-al Walid, potentially the single greatest military commander of all time. Who was Khalid ibn-al Walid? What does his life tell us about the chaotic world he was born into, the improbable spread of Islam, and the making of the modern Middle East?