Imperialism Notes: Definition of imperialism: The policy of extending your rule over foreign countries and conquering. Imperialism is empire building. Expansion occurs when one state is more powerful than are the obstacles to expansion. The obstacles may be other states or peoples, or they may be geographic or physical or technological obstacles. The first sustained European interest in Africa developed through the efforts of Henry the Navigator, prince of Portugal. Numerous expeditions were sent out after 1434, each extending European knowledge of the African coastline southward, until, in 1497-1498, Vasco da Gama rounded the Cape of Good Hope and reached India. The Portuguese explorations were motivated by a variety of impulses: a desire for knowledge, a wish to spread Christianity, the search for potential allies against Muslim threats, and the hope of finding new and lucrative trade routes to the east, and sources of wealth. Wherever the Portuguese - and the English, French, and Dutch who followed them - touched, they disrupted ongoing patterns of trade and political life and changed economic and religious systems. Trade Routes and the Slave Trade The Portuguese established a chain of trading settlements along the west African coast. El Mina, founded on the Gold Coast in 1482, was the most important; in fact, it was only on the Gold Coast and in the Kongo and Luanda areas that the Europeans found trade to be really lucrative. African gold, ivory, foodstuffs, and slaves were exchanged for ironware, firearms, textiles, and foodstuffs. The Portuguese attracted rival European traders who, in the 16th century, created competing stations or attempted to capture the existing trade. In western Africa the new trade had profound effects. Earlier trade routes had been oriented northwards across the Sahara, primarily to the Muslim world. Now the routes began to be reoriented to the coast, and as the states of the savannah declined in economic importance, states along the coast increased their wealth and power. Struggles soon developed among coastal peoples for control over trade routes and for access to the new firearms introduced from Europe.