The Sword and the Sun: The Old World Drought Atlas as a Source for Medieval Mediterranean History

<p> The release of the Old World Drought Atlas (OWDA) in November 2015 provides historians with an unprecedented glimpse into the climate of the medieval world. Through the careful examination of tree-ring data provided by the OWDA, historians can better gauge how the environment affected the course of medieval Mediterranean history, particularly in times and places where textual data is sparse, such as North Africa. The case studies of the Norman conquest of the coast of Ifr&imacr;qiyya in the 1140s and the invasion by the Ban&umacr; Hil&amacr;l in the mid-eleventh century show the utility of the OWDA for gaining a better understanding the medieval Mediterranean. In particular, OWDA data shows that the arrival of the Ban&umacr; Hil&amacr;l into Ifr&imacr;qiyya coincided with a period of extended drought that is not documented in the written sources and suggests that increased competition for scarce resources was instrumental to their entrance into the region.</p>