A 2014 estimate, based on the slave voyages database suggests the Atlantic slave trade removed at least 12.5 million individuals from Africa.
These numbers do not include those killed in the process of capture and collection. The journey from the interior to the coast could take many months. Slaves often travelled on foot in coffles - lines of captives shackled or bound together. It is possible many millions died during raiding and transporting.
Estimates suggest that 77 per cent of these slaves (10.1 million) were 'produced' along the West and West Central coasts of Africa during the 150 years between 1701 and 1850. This equates to 9.3 per cent of the total population of the coastal area.
By the end of the 17th century European demand for African captives, particularly for the sugar plantations in the Americas, became so great that they could only be acquired by initiating raiding and warfare. Large areas of Africa were devastated and societies disintegrated.
Depopulation was also caused indirectly. Europeans brought with them deadly diseases: eg European strains of syphilis and smallpox, typhus and tuberculosis.