he Islamic Golden Age was a period of cultural, economic, and scientific flourishing in the history of Islam, traditionally dated from the 8th century to the 14th century. This period is traditionally understood to have begun during the reign of the Abbasid caliph Harun al-Rashid (786 to 809) with the inauguration of the House of Wisdom in Baghdad, the world's largest city by then, where Islamic scholars and polymaths from various parts of the world with different cultural backgrounds were mandated to gather and translate all of the world's classical knowledge into Arabic and Persian. Several historic inventions and significant contributions in numerous fields were made throughout the Islamic middle ages that revolutionized human history.
The period is traditionally said to have ended with the collapse of the Abbasid caliphate due to Mongol invasions and the Siege of Baghdad in 1258. A few scholars date the end of the golden age around 1350 linking with the Timurid Renaissance, while several modern historians and scholars place the end of the Islamic Golden Age as late as the end of 15th to 16th centuries meeting with the Age of the Islamic Gunpowders. (The medieval period of Islam is very similar if not the same, with one source defining it as 900–1300 CE.)
The metaphor of a golden age began to be applied in 19th-century literature about Islamic history, in the context of the western aesthetic fashion known as Orientalism. The author of a Handbook for Travelers in Syria and Palestine in 1868 observed that the most beautiful mosques of Damascus were "like Mohammedanism itself, now rapidly decaying" and relics of "the golden age of Islam".
There is no unambiguous definition of the term, and depending on whether it is used with a focus on cultural or on military achievement, it may be taken to refer to rather disparate time spans. Thus, one 19th century author would have it extend to the duration of the caliphate, or to "six and a half centuries", while another would have it end after only a few decades of Rashidun conquests, with the death of Umar and the First Fitna.
During the early 20th century, the term was used only occasionally and often referred to as the early military successes of the Rashidun caliphs. It was only in the second half of the 20th century that the term came to be used with any frequency, now mostly referring to the cultural flourishing of science and mathematics under the caliphates during the 9th to 11th centuries (between the establishment of organised scholarship in the House of Wisdom and the beginning of the crusades), but often extended to include part of the late 8th or the 12th to early 13th centuries. Definitions may still vary considerably. Equating the end of the golden age with the end of the caliphates is a convenient cut-off point based on a historical landmark, but it can be argued that Islamic culture had entered a gradual decline much earlier; thus, Khan (2003) identifies the proper golden age as being the two centuries between 750–950, arguing that the beginning loss of territories under Harun al-Rashid worsened after the death of al-Ma'mun in 833, and that the crusades in the 12th century resulted in a weakening of the Islamic empire from which it never recovered.