The present work offers the first major study of the Augustinian historian and missionary Guillaume Bonjour (1670-1714) and places Bonjour's hitherto unstudied contributions to pagan mythography, biblical chronology, and ancient religion in their historical, intellectual context. It argues that Bonjour was part of a prominent scholarly tradition which advanced a new understanding of and approach to studying pagan antiquity, an approach which, if developed with the intention of elucidating and further confirming traditional assumptions about the authority of biblical history, nevertheless proved innovative for the way in which it postulated a new relationship between the "sacred" and the "profane" in ancient history.