Boundaries between the continentsDetermining the boundaries between the continents is generally a matter of geographical convention. Several slightly different conventions are in use. The number of continents is most commonly considered seven (in English-speaking countries) but may range as low as four when Afro-Eurasia and the Americas are both considered as single continents. An island can be considered to be associated with a given continent by either lying on the continent's adjacent continental shelf (e.g.
San peopleThe San peoples (also Saan), or Bushmen, are the members of the indigenous hunter-gatherer cultures of southern Africa, and the oldest surviving cultures of the region. Their ancestral territories span Botswana, Namibia, Angola, Zambia, Zimbabwe, Lesotho and South Africa. They speak, or their ancestors spoke, languages of the Khoe, Tuu and Kxʼa language families, and are only a 'people' in contrast to pastoralists such as the Khoekhoe and descendants of more recent waves of immigration such as the Bantu, Europeans and Asians.
Internal migrationInternal migration or domestic migration is human migration within a country. Internal migration tends to be travel for education and for economic improvement or because of a natural disaster or civil disturbance, though a study based on the full formal economy of the United States found that the median post-move rise in income was only 1%. Cross-border migration often occurs for political or economic reasons. A general trend of movement from rural to urban areas, in a process described as urbanisation, has also produced a form of internal migration.
History of colonialismThe historical phenomenon of colonization is one that stretches around the globe and across time. Ancient and medieval colonialism was practiced by the Phoenicians, the Greeks, the Turks, and the Arabs. Colonialism in the modern sense began with the "Age of Discovery", led by Portuguese, who became increasingly adventuresome following the conquest of Ceuta in 1415, aiming to control navigation through the Strait of Gibraltar, expand Christianity, obtain plunder, and suppress predation on Portuguese populations by Barbary pirates as part of a longstanding African slave trade; at that point a minor trade, one the Portuguese would soon reverse and surpass.
Christianity in AfricaChristianity in Africa first arrived in Egypt in approximately 50 AD. By the end of the 2nd century it had reached the region around Carthage. In the 4th century, the Aksumite empire in modern-day Ethiopia and Eritrea became one of the first regions in the world to adopt Christianity as its official religion. The Nubian kingdoms of Nobatia, Makuria and Alodia followed two centuries later. From the late fifth and early sixth century, the region included several Christian Berber kingdoms.
