Abd al-Rahman III (891-961) was the greatest of the Umayyad rulers of Spain and the first to take the title of Caliph. During his reign Islamic Spain became wealthy and prosperous.

Abd al-Rahman III, called al-Nasir or the Defender (of the Faith), was born at Cordova on Jan. 7, 891, the son of Prince Muhammad and a Frankish slave. Like most of his family, he was blue-eyed and blond, but he dyed his hair black to avoid looking like a Goth. In 912 he succeeded his grandfather, Abd Allah, as emir. The first period of his half-century reign was marked by campaigns of pacification against various rebellious groups. Between 912 and 928 he steadily wore down the forces of Umar ibn Hafsun, whose coalition of neo-Moslem peasants from southern Spain proved the most serious challenge yet mounted against Cordova's authority.

During the next phase of his reign Abd al-Rahman was able to concentrate...