the 16th century, Spanish and Portuguese explorers were the first Europeans to begin trade in Nigeria, in the port they named Lagos and in Calabar. The Europeans traded goods with the peoples of the coast. Soon they also negotiated for a portion of the existing African slave trade. Traditionally, peoples captured in war were made slaves by the conquerors. Usually they were taken back to the conquerors' territory, put to work and sometimes acculturated and eventually absorbed into the other culture. When the Europeans entered the trade, they transported slaves mostly to the Americas to work as laborers. Particularly in what became the United States, slavery became a permanent racial caste to which people of African descent were confined. The demands of the slave trade produced a greater market in slaves than had existed before. Nigerian ethnic groups were transported to the Americas and the Caribbean as part of the African diaspora of slavery.
The slave trade was joined by Great Britain and France. The colonial era is considered to date from 1800, when Great Britain did With rising anti-slavery sentiment in Great Britain, it abolished its international slave trade in 1807 together with the United States. Following the Napoleonic Wars, Great Britain established the West Africa Squadron in an attempt to halt the international traffic in slaves. It stopped ships of other nations that were leaving the African coast with slaves; sometimes it would take the freed slaves to Sierra Leone, its colony in West Africa, rather than return the people to the risk of renewed slavery in other coastal states.
In 1885, British claims to a West African sphere of influence received recognition from other European nations. The following year, it chartered the Royal Niger Company under the leadership of Sir George Taubman Goldie. In 1900 the company's territory came under the control of the British government, which moved to consolidate