Excerpts from Books and Wikipedia
The first challengers to Abbasid rule came from the Fatimid rulers of Egypt in 910. However, the Fatimids were Shi'ites and considered heretics by the Sunni majority. Abd ar-Rahman was the first Sunni ruler to reject the Abbasid caliphs. [Furtado: 1001 Days] "In the days of this father and son al-Andalus could boast of four hundred flourishing towns and cities, seventeen colleges and universities, and seventy well-stocked libraries. Cordova alone had six hundred mosques, nine hundred public baths and eighty schools." [Balyuzi: Muhammad and Course of Islam, p. 304]