Few figures in world history have left as durable an impression on modern society as the caliph Hārūn al-Rashīd. Whereas the names of famous figures are usually associated with a specific achievement, era, or event, Hārūn's name is familiar enough without reference to either a chronological frame or an actual physical setting. His reign, as one publisher in the Victorian age wrote in trying to promote a biography of the caliph, “belongs to all time and no time,” an era idealized in later imagination to symbolize an age of fabulous prosperity, a resplendent court, and an Islamic empire whose realm stretched as far as the caliph desired. The name of the caliph has been so synonymous with the concept of a golden age of medieval Islamic civilization that his biographies have generally provided occasions for describing the origin of Islam, the spread of the Arab conquests under the Umayyads, and the sophistication of cultural life in Damascus and Baghdad, as well as in Cordoba.

Trying to sketch the line between myth and fact in the portrait of the caliph has long been a shadowy exercise, and generations of the caliph's admirers have generally, and probably intentionally, been content to let the ambiguity remain.