Note to the Reader
Due to the great number of proper names in the text, I have preferred not to transliterate them for the sake of clarity. Transliteration is used only in the bibliography and for Arabic terms at their first appearance in the text.
The transliteration follows the system commonly used in publications in the English language.
To facilitate the identification of named persons, the year of their death, converted into the Christian era, has been added to their names. Whenever the month is not indicated in the source, the two alternative years are given.