Before World War II many African countries were ruled by a handful of European nation how did many of the colonies achieve independence in the decades following the war

Ever since world war 2, 51 states have achieved their independence, either through wars or political means. That does not mean of course that all 51 still exist to this date or that those that do exist are same as in the time period when they acheived their independence. Only 2 African countries managed to do it before world war 2, Egypt in 1922, and South Africa in 1910.