Ali Osman's Economy and trade of medieval Nubia is premised on the notion of continuity across Nubian history. With this probably fair assumption, his thesis proceeds to explore possible mechanisms and systems of economics and exchange in Nubia based on analogous practices in modern Nubia. This can be justified by the, again, probably fair, conclusion that relations with their environment, technology, and rural/village systems of land proprietorship and lineages have not changed drastically until the 20th century. While Osman is undoubtedly correct to point to the necessity of using contemporary Nubian ethnographic and linguistic evidence to make sense of Christian Nubia, his analogous model does veer a little too far by attempting to compare Nubia's river trade of the early 20th century to the organization of trade 1000 years ago. Again, the environment hasn't changed that much and there undoubtedly was much continuity at the village level (at least) from the Christian period through post-Christian kingdoms. But, one suspects that the impact of religion and the gradual shift to Islam may have introduced more changes in social, economic, spiritual, and political features than we think. Despite some similarities between the state of Kokka, for instance, and medieval Nubia, the practice of Islam and changes in the "superstructure" of society may have introduced or led to other changes on the micro-level. Despite our own hesitations about some of the study's conclusions, it was fascinating to read Osman's personal, autobiographic details. Indeed, oral traditions of his own lineage identify a Christian ancestor who lived several centuries ago! And the author's comments about official versus popular trade seem reasonable.