The Abbasid Caliphate (750–1258) is often referred to as the Golden Age of Islam. This was a period in which the Baghdad- based caliphs of the Abbasid dynasty not only controlled an empire stretching from Central Asia to North Africa but also presided over an unparalleled flourishing of art, science, mathematics, medicine, and philosophy. Among the reasons for the Golden Age was the caliphate’s broad cultural and intellectual diversity. Since the time of Muhammad (571–632), Arab armies had systematically (and rapidly) conquered the Arabic peninsula, the Middle East, and Persia in the East, and Egypt, North Africa, and Spain in the West. Within several generations, members of acculturated, conquered minorities, in particular scientists and mathematicians from Persia and physicians and philosophers from the formerly Christian domains of the Byzantine Empire, were making significant contributions to Islamic culture.