The Atlantic slave trade or transatlantic slave trade involved the transportation by slave traders of enslaved African people to the Americas. This trade was operated by slave ships from both Europe and the New World. Some voyages used the triangular trade route and its Middle Passage, particularly in the early phases. Europeans established a coastal slave trade in the 15th century, and trade to the Americas began in the 16th century, lasting through the 19th century. Most transported in the transatlantic trade were from Central and West Africa. In contrast to other slave trades, those taking slaves from Africa generally bought their cargo from West and Central African slave merchants. This applied to Europeans in the transatlantic trade and Arab slave traders supplying their own markets. While Europeans were involved in some raiding, this was uncommon and discouraged. The Portuguese built barracoons in their African slaving bases to gather newly purchased captives ready for the next ship to arrive. Northern Europeans operated some forts as African bases, originally for trading in gold, but later for slaves. However, the usual approach of North European slave traders was to use their ship as a base in which to gather their cargo. This meant these ships spent much longer on the African coast than Portuguese vessels, and the first slaves the slavers bought endured longer confinement on board.