Middle Ages
The Middle Ages were a golden age of knowledge in Muslim territories. Europe was struggling greatly, but the Islamic world was making great progress in the arts, agriculture, economics, industry, law, literature, navigation, philosophy, sciences and technology.  Many Muslim caliphs and Sultans gathered the ancient texts of great classical empires. (For example, the caliphs of Andalusia, based in Cordoba, gathered ancient Roman texts, and the Anatolian Seljuk Sultans gathered ancient Greek texts.). During the Islamic Golden Age, Al-Khwarizmi, a Persian Muslim mathematician, helped to develop algebra.