Two years later, the Royal African Company was inaugurated, receiving from King Charles a monopoly of the trade to supply slaves to the British colonies of the Caribbean.  From the outset, slavery was the basis of the British Empire in the West Indies. Until the abolition of its slave trade in 1807, Britain was responsible for the transportation of million African slaves to the Americas, a third of all slaves transported across the Atlantic .  To facilitate this trade, forts were established on the coast of West Africa, such as James Island , Accra and Bunce Island . In the British Caribbean, the percentage of the population of African descent rose from 25% in 1650 to around 80% in 1780, and in the Thirteen Colonies from 10% to 40% over the same period (the majority in the southern colonies).  For the slave traders, the trade was extremely profitable, and became a major economic mainstay for such western British cities as Bristol and Liverpool , which formed the third corner of the triangular trade with Africa and the Americas. For the transported, harsh and unhygienic conditions on the slaving ships and poor diets meant that the average mortality rate during the Middle Passage was one in seven. 
The company also had interests along the routes to India from Great Britain . As early as 1620, the company attempted to lay claim to the Table Mountain region in South Africa , later it occupied and ruled the island of Saint Helena. The company also established Hong Kong and Singapore ; and cultivated the production of tea in India . Other notable events in the company's history were that it held Napoleon captive on Saint Helena , and made the fortune of Elihu Yale (1649-1721) the benefactor of Yale College, Boston. Its products were the basis of the Boston Tea Party in Colonial America.