The translation movement in the Abbasid period made Baghdad a global center of knowledge, especially in the time of the caliph al-Ma´mun (reigned 813–833), the founder of the House of Wisdom, where diverse scientific texts on Greek, Syraic, Indian, and Persian were translated into Arabic. This knowledge was transferred to al-Andalusia by travelers and traders and turned cities like Cordoba (in the tenth and eleventh centuries) and Toledo into scientific centers similar to Baghdad. Even European scholars were traveling to study in al-Andalus as early as the end of the tenth century. In the school of Toledo, many works were translated, usually from Arabic into Castilian, and then from Castilian into Latin, or directly from Arabic into Latin or Greek. Thanks to all those activities, very important texts from Arabic, Hebrew, and Greek philosophers and scientists became known and available in Europe, which was of fundamental importance for the later developments in the Renaissance.
Three types of sources concerning the eighth and ninth centuries were investigated: geographical works, historical literature, and literary works in Arabic by Muslim authors. Such sources are only taken into consideration as secondary sources for all the studies of the history of Islamic sciences. The texts show, for the eighth and ninth centuries, a large extended scholarly network extending from Central Asia and India to Syria. They comprise scholars of different disciplines: medicine, engineering, astronomy, astrology, mathematics, and philosophy. The scholars are also ethnically and religiously diverse: Arabs, Syrians, Persians, and Indians; Muslims, Christians, Jews, Zoroastrians, and Hindus.
Because traveling for educational purposes has been regarded as a central element in the creation of intellectual elites in al-Andalus for the period between about 800 and 1250, a collection of sources has been compiled documenting travelers and goods between (Umayyad and Abbasid) capitals and local centers of power in al-Andalus, the Maghrib, and Khurasan in the period between 700 and 1250. The sources show that the new principalities on the Iberian Peninsula served as hubs for the transfer of knowledge and books from the Islamicate centers during the tenth, eleventh, and twelfth centuries.