This is a very good work of scholarship. The title of the book comes from the story of Ham, who saw his father Noah naked. When Noah awoke, he cursed Ham's son Canaan: "Cursed be Canaan, a slave of slaves shall he be to his brothers" (Gen 6.25). Goldenberg sets the stage by noting the use made of this and other biblical stories (specifically from the Hebrew bible, what Christians call the Old Testament) in justifying racism and slavery.
He begins his scholarly analysis by going back and looking at issues of race and slavery when these stories originally came into circulation. He concludes that skin color was initially understood much as any other physical trait was understood. He noted that in most cultures (including the Hebrew culture of the Middle East) there was an aesthetic preference for the skin tones of one's own people, though the preference was for women to be lighter skinned than men. He did not find any prejudice against black Africans among the early Hebrews, nor a tendency to associate one particular race or ethnic group with enslavement. (Although the curse of Canaan/Ham is the centerpiece of his research, he looks carefully at all possible references to race and skin color in the Bible, including the passage in the Song of Solomon, "I am very dark, but comely.")
Goldenberg then traced later interpretations of biblical texts to introduce some of the elements of later interpretations. He noted that most commentators had a problem with Canaan receiving a curse for what his father Ham had done (and also, why not all of Ham's children?). Attempts to explain this away eventually became meshed with imposition of later ideas about skin color and slavery. Goldenberg marks the big shift in outlook, however, to the Muslim conquests in Africa, which introduced large numbers of black African slaves into the Mediterranean world. At this point, the equation of descendents of Ham/Canaan=black Africans=slaves became the standard interpretation of the biblical text and an underlying assumption of other references to Africa and Africans in the Bible and biblical commentaries, as well as in interpretations of the Quran.
Goldenberg is very strong in his analysis of early Hebrew texts and culture and in showing how later cultural changes led to new interpretations of these texts. He brings in references to attitudes in surrounding cultures (Greek and Roman ideas about race and ethnicity) but he makes these comparisons almost as asides, they are so brief.