This variety of Romance is the first documented in writing in the Peninsula as choruses (kharjas) (9th century) in Arabic lyrics called muwashahas. As they were written in Arabic alphabet, the vowels had to be reconstructed. In some aspects, it is more archaic than the other Romance languages.
This Romance variety had a significant impact in the formation of Portuguese, Spanish and Catalan (especially the Valencian variety), which explains why these languages have so many words of Arabic origin (Mozarabic was, understandably, quite influenced by Arabic and vice versa).
The cultural language of Mozarabs continued to be Latin, but as time passed, young Mozarabs studied and even excelled at Arabic.
MOZARAB [Spanish Mozdrabe, a corruption of the Arabic Musta`rib, coll.
It was applied by the Moslems in Spain to the Christian communities existing among them, in Cordova, Seville, Toledo and other large cities, in the exercise of their own laws and religion.
The ancient liturgy used by the Christians of Toledo is commonly known as Mozarabic.