The Islamic Golden Age coincided with the Middle Ages in the Muslim world, starting with the rise of Islam and establishment of the first Islamic state in 622. The end of the age is variously given as 1258 with the Mongolian Sack of Baghdad, or 1492 with the completion of the Christian Reconquista of the Emirate of Granada in Al-Andalus, Iberian Peninsula. During the reign of the Abbasid caliph Harun ar-Rashid (786 to 809), the legendary House of Wisdom was inaugurated in Baghdad where scholars from various parts of the world sought to translate and gather all the known world's knowledge into Arabic. The Abbasids were influenced by the Quranic injunctions and hadiths, such as "the ink of a scholar is more holy than the blood of a martyr," that stressed the value of knowledge. The major Islamic capital cities of Baghdad, Cairo, and Córdoba became the main intellectual centers for science, philosophy, medicine, and education. During this period, the Muslim world was a collection of cultures; they drew together and advanced the knowledge gained from the ancient Greek, Roman, Persian, Chinese, Indian, Egyptian, and Phoenician civilizations.

When did the Islamic Golden age start?