The Islam's Golden age lasted for five centuries. The Golden age started in the 8th century and ended in the 13th century. It was actually during the middle ages that Islam flourished most and during this period various Caliphates ruled. It is called the Golden age because during this period their was great developments in the field of science, culture and economy. Harun-al Rashid is considered the pioneer for starting this Golden Age. The Muslims during this great period tried to absorb the scientific developments that took place in the empires they captured. This resulted in their overall growth to fame.