Mohammad found the custom existing among the pagan Arabs...

Mohammad found the custom existing among the pagan Arabs; he minimised the evil, and at the same time laid down such strict rules that but for the perversity of his followers, slavery as a social institution would have ceased to exist with the discontinuance of the wars in which the Moslem [sic] nation were at first involved.

The mutilation of the human body was also explicitly forbidden by Mohammad, and the institution which flourished both in the Persian and the Byzantine empires was denounced in severe terms. Slavery by purchase was unknown during the reigns of the first four Caliphs, the khulafai-rashidin, 'the legitimate Caliphs' as they are called by the Sunnis. There is, at least, no authentic record of any slave having been acquired by purchase during their tenure of office.

But with the accession of the usurping house of Ommeyya [sic] a change came over the spirit of Islam. Mu'awiyah was the first Muslim sovereign who introduced into the Mohammedan world the practice of acquiring slaves by purchase. He was also the…