From 712 to 1085 the Spanish city Toledo–now one of the most visited tourist cities of Spain–belonged to the Moors, who called it Tulaytula. By that time, Europe had slowly forgotten all the achievements of the Greeks and Romans, having deteriorated into some muddy backwater of overall illiteracy and grubbiness, but the Arab world kept rapidly developing. Nowadays it’s hard to imagine that back then science prospered in Bagdad, Cairo, Cordoba, and Toledo, rather than in Rome, London, or Paris.
In 1055, the Russian knyazhna Anna, married to the French king, wrote in horror to her father, Yaroslav the Wise, the Grand Prince of Kiev, “Dear Father, they wash themselves only once a year here!… The dwellings are gloomy, the churches are ugly, and the mores are terrible… No king here is able to read… Where did you send my sinful soul? To this stinking hole, to France, to this damned city of Paris!…”
By the way, Anna Yaroslavna knew three other languages apart from Russian: Greek, Latin, and French.
Meanwhile the work of translating all writings of the Greek scientists that could be found during trips to Asia Minor was in full swing in the Arab Muslim Caliphate. All the bright minds of the empire assembled in Bagdad. They were well paid only for a single purpose–to keep developing science and art. Moreover, nobody ever demanded proof that the research would result in practical use.