The Islamic Golden Age was a period of cultural flourishing in the history of Islam, dated from the 8th century CE to the 14th century. The period is understood to have begun during the reign of the Abbasid caliph Harun al-Rashid (786–809), with the establishment of the House of Wisdom in Baghdad, one of the world's largest cities at the time. The institution attracted scholars from across the Muslim world to translate the classical knowledge of the known world into Arabic and later into Persian as well. In addition to Baghdad, the intellectual and cultural activity also flourished in other urban centers of the medieval Islamic world, including Cairo, and Umayyad Córdoba, as well as Damascus, Nishapur, Samarkand, Ghazni, Kairouan, and Fez, and in later centuries, Nasrid Granada.