The Prophet Muhammad (570–632), who was born in Saudi Arabia and died in Medina, was the founder of Islam. At the age of 40, he experienced an epiphany in which the angel Gabriel appeared to him while he was meditating. Until he was 60, he experienced continuing revelations that identified him as the culmination of a tradition of prophets from Abraham in the Old Testament, or Hebrew Bible, down to Jesus of Nazareth in the New Testament. His transcription of his revelations were the basis of the Qur’an, or Koran, the bible of Islam.

Muhammad had a divine mandate to spread the new religion. Within the first 100 years of Islam, jihad, or holy war, reached into France, where Charles the Sledgehammer defeated the Muslims at Tours; in Spain, the Moors built luscious gardens and beautiful buildings, chief among which were the magnificent libraries in Córdoba, Granada, Seville, and Toledo. (The Muslim cultural influence is still evident in Spanish architecture to this day.)