The Bayt al Hikmah (House of Wisdom) was a major intellectual center during the Islamic Golden Age. The House of Wisdom was founded by Caliph Harun al-Rashid and culminated under his son al-Ma'mun who is credited with its formal institution. Al-Ma'mun is also credited with bringing many well-known scholars to share information, ideas and culture in the House of Wisdom. Based in Baghdad from the 9th to 13th centuries, many learned scholars including those of Persian or Christian background were part of this research and educational institute. Besides translating books into Arabic and preserving them, scholars associated with the House of Wisdom also made many remarkable original contributions to diverse fi elds. During the reign of al-Ma'mun, astronomical observatories were set up, and the House was an unrivaled center for the study of humanities and for science in medieval Islam, including mathematics, astronomy, medicine, alchemy and chemistry, zoology and geography and cartography. Drawing on Indian, Greek, and Persian texts, the scholars accumulated a great collection of world knowledge, and built on it through their own discoveries. By the middle of the ninth century, the House of Wisdom was the largest repository of books in the world.