The book covers a period from the beginning of Islam, up to the beginning of the sixteenth century, and deals mainly with the eunuchs in the major centers of Islam in the East (Umayyads, 'Abbāsids, Seljuks, Zengids, Ayyūbids and Mamlūks and to some extent, the Fāţimids of Egypt). It is not a history of the eunuchs in that wide area but rather is mainly concerned with the power accumulated by the eunuchs, militarily, socially and even economically (especially as trustees of financial affairs and property). The ultimate aim of the study is to bring out the close ties connecting the harem, the eunuchs and the Mamlkūs. In all of these three areas, the dominant element had been slaves (Islamized and often enfranchised) who were imported beyond the lands of Islam. The eunuchs were usually the upbringers of the young Mamlkūs and quite often their commanders. The Mamlkūs themselves, in various and changing forms, constituted the mainstay of Islam to the harem, the eunuchs and the Mamlūks. In all of these three areas, the dominant element had been slaves (Islamized and often enfranchised) who were imported beyond the lands of Islam. The eunuchs were usually the upbringers of the young Mamlūks and quite often their commanders. The Mamlūks themselves, in various and changing forms, constituted the mainstay of Islam's military might through the greatest part of its existence. Other subjects discusses are castration's, the eunuchs prices, and their so-called sexual life, romances as a well as their marriages.