Perhaps there could not have been a more succinct summary of the pristine position of Zanzibar in the commercial economy of East Africa during the nineteenth century than in the quotation given above. The economy was based on two definable sectors, production on the offshore islands themselves, and the transit trade. The two sectors, however, were not isolated from each other, and the former was increasingly subordinated to the latter as the century progressed. Each sector threw up its own dominant class which collaborated as well as competed with the other, increasingly under the overall hegemony of international capitalism.

On the islands of Unguja and Pemba there had developed slave-based production of cloves, coconuts and sugar, largely for export. Between 1859 and 1870-1 available data indicate that products originating from the islands contributed an average of 22 per cent of the total value of exports of Zanzibar (see Table 4.1). Since the slave system depended on the slave trade, which was largely financed by merchant capital; most of the cloves were exported by the merchants; and, finally, large parts of the clove plantations were increasingly mortgaged to moneylenders, this meant that the ruling class in Zanzibar, predominantly Omani landowners during the first half of the nineteenth century, was gradually being subordinated economically to the merchant class.

The rest of the exports of Zanzibar during these years originated from a vast hinterland on the African mainland which extended far beyond Zanzibar's actual sovereignty. Its entrepot role developed partly from geographical factors which were, however, activated by economic and political factors during the eighteenth and nineteenth centuries. Zanzibar is located within the belt of reliable monsoons that controlled shipping in the Indian Ocean before the age of steam.