Fernão de Oliveira Denounces the Slave Trade The Portuguese sailor Fernão de Oliveira, in Arte de Guerra no mar (The Art of War at Sea), denounces the slave trade as an ‘evil trade’. The book anticipates many of the arguments made by abolitionists in the eighteenth and nineteenth centuries. See the Source John Lok Hopes to Bring London into Slave Trade A small group of Africans from Shama (modern Ghana) are brought to London by John Lok, a London merchant hoping to break into the African trade. See the Source