Guinea, the name of a large section of the west coast of Africa, which first came into general use in the 15th century, and is generally applied to the stretch of coast-lands extending from the mouth of the Senegal, in about 14° N. lat., to Cape Negro, in 16° S. lat. By conventional usage it is further divided into two parts, Upper and Lower Guinea, the dividing line being taken variously as the equator, the Gaboon, the Ogoway. The coast-line is throughout tolerably uniform, and everywhere flat, with numerous shallow lagoons separated from the ocean by narrow spits of sand, lying parallel to the coast. Proceeding inland, the country rises to the central plateau of the continent by a series of broad terrace-like steps, down which the longer rivers are generally precipitated in cataracts and rapids. The Ivory Coast, the Gold Coast, the Slave Coast, are names for portions of the coast between Liberia and the Niger mouths. Some part of Guinea belongs to native states and some to the Liberian republic ; most of it is now cut up into dependencies of Britain, France, Germany, Spain, Portugal, in somewhat inconvenient fragments. The Genoese claim to have been the first Europeans to reach (in 1291) the coasts of Guinea. They were, however, first regularly visited, from 1364 onwards, by merchant adventurers from Rouen and Dieppe, and first colonised in 1481 by the Portuguese, under Prince Henry the Navigator.