For Islam, the city is a key factor in its model of civilization. When the Muslims arrived in the Ebro Valley in 714, they only found three urban centers: Tarazona, Zaragoza, and Huesca. Between the late 8th and early 9th centuries, they founded Calatayud, Mequinenza, and Daroca. Around the year 900, they refounded Ejea and Barbastro, and shortly after, Albarracín (as well as many other locations such as Alquézar, Caspe, or Alcañiz). All of these, both old and new medinas, would thrive as prosperous and highly commercial cities.
Medinas where fortresses, markets, mosques, and palaces were created, where coins were minted, and crafts such as textiles, ceramics, construction, and metallurgy developed. Above all, Zaragoza (Saraqusta) stands out: first as the capital of the Upper March, then as an independent taifa or kingdom, a significant center of political, economic, and intellectual power. In Saraqusta, for example, the great Ibn Bayyah, Avempace, was born and lived: philosopher, physician, botanist, astronomer, mathematician, musician, poet, and vizier. He was a true paradigm of the Andalusian scholar.