In Roman religious and political thought, it was the favouring of Rome by the city's chief and supreme god, Jupiter Optimus et Maximus, in conjunction with Rome's attention to religious matters, that had led to the establishment of the Roman Empire and Rome's ascendancy over the Mediterranean world. For the Romans themselves, their dominion over the known, 'civilized' world, was not only the result of feats of arms or superior strategy, tactics and soldiering. Rather, it was their firm belief that it was the gods who had ordained that the Romans would conquer the world. This aspect of Roman imperialism, and their imperium - rule - has received attention from scholars, especially with respect to individual topics such as a Roman general in battle devoting his life to the gods (the devotio ritual), when a Roman commander sacrificed himself to achieve victory, and topics such as the declaration of war as a religious ceremony. But there is certainly room for more scholarship about Roman warfare and the beliefs concerning the involvement of the Roman gods in this. In this volume, eight international scholars of Roman warfare examine crucial aspects of Roman warfare and its connection with the gods. The period covered is the Roman Republic (509-27 BC), while a companion volume on the Roman Empire deals with the same themes in relation to the imperial period.