Answer:
There are a number of reasons.
Explanation:
From the 15th century there have been European colonies in Africa. An early reason was establishing trading bases for example for the spice trade. So establishment and control of ports was important.
Secondly there was the growth of the slave trade. European countries established colonies particularly in West Africa, and developed good relations with local chiefs. as a consequence millions of Africans were captured and sold into slavery.
Thirdly there have been strategic reasons. The construction of the Suez Canal through British controlled Egypt meant that the British and the French controlled access from the Mediterranean into the Red Sea and Indian Ocean.
There was also imperial rivalry. Countries such as Belgium in the Congo, and Germany in what is now Namibia, established brutal colonies as a statement of their status in the late 19th century.
There is also the question of natural resources. The list is almost endless, for example gold and diamonds in South Africa.
