 By the 19th century , European colonialism in Africa had reached its height . Having lost control of the vast territory of Brazil in South America , the Portuguese began to focus on expanding their African outposts . This brought them into direct conflict with the British . Since David <unk> had returned to the area in 1858 in an attempt to foster trade routes , British interest in Mozambique had risen , <unk> the Portuguese government . During the 19th century , much of Eastern Africa was still being brought under British control , and in order to facilitate this , Britain required several concessions from the Portuguese colony . 
