this highlights European missionaries colonizing African continent using the trick of claiming to bring light in the so called "Dark continent" only to trick the Africans which were mainly Moroccans and Algerians.
though i was no able apply annotations, this article highlights the discussions between the Portuguese and the British upon the Treaty which would ban slavery in the coast of Africa, but the Treaty could only last for 3 years. the Portuguese did not hold much power as the British therefore, the British had the final say.