<P> The Portuguese established the first firm post-Middle Ages European settlements, trade posts, permanent fortifications and ports of call along the coast of the African continent, from the beginning of the Age of Discovery during the 15th century . But Europeans showed comparatively little interest in (and less knowledge of) the interior for some two centuries thereafter . </P> <P> European exploration of the African interior began in earnest at the end of the 18th century . By 1835, Europeans had mapped most of northwestern Africa . In the middle decades of the 19th century, famous European explorers included David Livingstone and H.M. Stanley, each of whom mapped vast areas of Southern Africa and Central Africa . Arduous expeditions in the 1850s and 1860s by Richard Burton, John Speke and James Grant located the great central lakes and the source of the Nile . By the end of the 19th century Europeans had charted the Nile from its source, traced the courses of the Niger, Congo and Zambezi Rivers, and realised the vast resources of Africa . </P> <P> Even as late as the 1870s, European states still controlled only ten percent of the African continent, with all their territories located near the coast . The most important holdings were Angola and Mozambique, held by Portugal; the Cape Colony, held by the United Kingdom; and Algeria, held by France . By 1914, only Ethiopia and Liberia remained independent of European control . </P> <P> Technological advances facilitated European expansion overseas . Industrialisation brought about rapid advancements in transportation and communication, especially in the forms of steam navigation, railways and telegraphs . Medical advances also played an important role, especially medicines for tropical diseases . The development of quinine, an effective treatment for malaria, made vast expanses of the tropics more accessible for Europeans . </P>

What two countries in africa remained free from imperial control