All events · The Medieval World

The Red Sea and Indian Ocean Slave Trades, 7th–15th Centuries

c. 700–1450 · Sub-Saharan Africa

Displacement

Displaced

2 million

On the order of 1 to 3 million over roughly seven centuries. As with the Saharan trade there is no register: the figure derives from Ralph Austen's separate censuses of the Red Sea and Indian Ocean routes and from Paul Lovejoy's synthesis, built from port references in Arabic and Persian geographers, later observed volumes and assumptions about continuity. Specialists working on the Swahili coast regard the medieval leg as the least securely quantified of all the slave trades, and the estimate should be read as an order of magnitude.

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What happened

Alongside the Saharan routes, a maritime trade carried enslaved people from the East African coast, the Horn and the Nilotic Sudan across the Red Sea and the Indian Ocean into Arabia, the Gulf, Iraq and India, where they served as domestic and agricultural labour, concubines and soldiers. The trade is visible in Arabic and Persian geographies, in the presence of East Africans in Abbasid Iraq — the Zanj of the ninth-century revolt were its product — and in the African-descended Habshi and Siddi communities that later held political power in parts of India. Estimates of volume for the medieval centuries are extrapolations rather than counts; the commonly cited totals of one to three million rest on Austen's censuses and Lovejoy's synthesis and are acknowledged by their authors to be provisional. The trade continued and expanded into the nineteenth century, so figures quoted for 'the Indian Ocean slave trade' often cover a far longer span than the medieval period treated here.

Parties

Merchants operating from the Swahili coast, the Horn and the Red Sea ports carried enslaved East Africans and Ethiopians to Arabia, the Persian Gulf, Iraq and India, in a trade organised through Islamic commercial networks

Disputed

The medieval volume of this trade is the least well evidenced of the major slave trades; the figures are extrapolations from later observed volumes and scattered references, and different specialists produce estimates differing by a factor of two or more.

The denominator

No defensible denominator exists. The trade drew captives over seven and a half centuries from the Horn, the Ethiopian highlands, the Swahili hinterland and, later, the Great Lakes - societies for which no contemporary counts exist and whose populations changed enormously across the period. The volume estimates themselves, by Ralph Austen and Paul Lovejoy among others, are reconstructions from port records, tariff yields and traveller accounts, with wide margins.

The figure is a cumulative total across 750 years and cannot meaningfully be set against any single population.

Where the baseline comes from

Indian Ocean slave tradeopen-edited
Arab slave tradeopen-edited

On the death toll

No defensible figures. Mortality in capture, on the coastal march and on the sea crossing is attested qualitatively but never counted for the medieval period.

Documented forms of violence

Forced Labour

Enslavement and transport for labour and domestic and sexual servitude is documented in the Arabic and Persian geographical literature and reconstructed in the Cambridge World History of Slavery and in Austen's and Lovejoy's censuses.