The peoples who migrated into Sierra Leone from this time would have had greater contact with the indigenous slave trade, either practicing it or escaping it. When Europeans first arrived at Sierra Leone, slavery among the African peoples of the area was believed to be rare. According to historian Walter Rodney, the Portuguese mariners kept detailed reports, and so it is likely if slavery had been an important local institution that the reports would have described it. There was mention of a very particular kind of slavery in the region, which was:   According to Rodney, such a person would likely have retained some rights and had some opportunity to rise in status as time passed. If the Africans were not much interested in acquiring slaves, the Portuguese—as well as the Dutch, French, and English who arrived later—certainly were. Initially, their method was to cruise the coast, conducting quick kidnapping raids when opportunities presented themselves. Soon, however, they found locals willing to partner with them in these affairs: some chiefs were willing to part with a few of the less-desirable members of their tribes for a price; others went into the war business—a large group of battle captives could be sold for a fortune in European rum, cloth, beads, copper, or muskets. This early slaving was essentially an export business. The use of slaves as labourers by the local Africans appears to have developed only later. It may first have occurred under coastal chiefs in the late 18th century:  For example, in the late 18th century, chief William Cleveland had a large "slave town" on the mainland opposite the Banana Islands, whose inhabitants "were employed in cultivating extensive rice fields, described as being some of the largest in Africa at the time". The existence of an indigenous slave town was recorded by an English traveler in 1823. Known in the Fula language as a "rounde", it was connected with the Sulima Susu's capital city, Falaba. Its inhabitants worked at farming. Rodney has postulated two means by which slaving for export could have caused a local practice of using slaves for labour to develop:  There are possible additional reasons for the adoption of slavery by the locals to meet their labour requirements:  This local African slavery was much less harsh and brutal than the slavery practiced by Europeans on, for example, the plantations of the United States, the West Indies, and Brazil. The local slavery has been described by anthropologist M. McCulloch:  Slaves were sometimes sent on errands outside the kingdoms of their masters and returned voluntarily.