It all started when Islam was spreading. The Land which is now Spain and Portugal used to be roman empire but it fell. When the Islamic Ummayad Caliphate ordered Amazigh (Berbers North Africa)from current Morocco as leader Tariq ibn Zijad together with his berber army, arab army + few jews and afro black Africans in minority to the land. They conquered it

• Islam became the main religion.
• Jews and Christians could have their own churches and synagogues but they had to pay tax to the muslims for protection (Army). But muslims also did pay tax.
• Jews and other non muslims could get high jobs in the caliphates.
• Bagdad was the center of the world of learning, many scolars went there to learn and then spread in to the whole Caliphate from Al-Andalusia to Bagdad.
• Better civilization than other European countries.
• Hospitals, surgery, better medicine and medical treatment was all around the muslim countries. Also don't mistaken that the Al-Andalusia was onlh ruled by Arabs and Berbers because alot of natives from Current spain and Portugal converted and lead people. There were mixed people too. Arabs marrying native spain people and stuff.