Well, according to one prominent writer on the subject, Dr. Imtiaz Habib, what notions of race the Elizabethans had were hopelessly confused, as they routinely combined Africans with Arabs, [and] Indians [with] south Asians and pre-Columbian Americans ... Indeed ... blacks and Indians were necessarily interchangeable in the Elizabethan popular mind..

It's instructive to compare this with the names used for the antagonists in mummers' plays: Prince Saladin, Blackamoor, Black Morocco King....