In the mid-seventh century, a new power emerged from the Arabian Peninsula that permanently altered the course of human history. Based on the scholarly work The Great Arab Conquests: How the Spread of Islam Changed the World We Live In by historian Hugh Kennedy, these conquests represented an "astonishing remaking of the political and religious map of the world," occurring at a speed that eclipsed even the expansion of the Roman Empire. The Speed and Scale of Expansion
: Historians often attribute this rapid success to the military exhaustion of the Byzantines and Persians after decades of mutual warfare, as well as the high degree of mobilization and ideological coherence within the early Muslim community. Cultural and Linguistic Transformation
: By the mid-eighth century, the caliphates controlled roughly 13 million square kilometers, including the Iberian Peninsula (Spain), North Africa, the Levant, and Central Asia.