The Benin Empire (14401897) was a pre-colonial African state in what is now modern Nigeria. It is not to be confused with the modern-day country called Benin (and formerly called Dahomey). Manillas are penannular armlets, mostly in bronze or copper, very rarely gold, which served as a form of commodity money (and, to a degree, ornamentation) among certain West African peoples (Aro Confederacy, Guinea Coast, Gold Coast, Calabar and other parts of Nigeria, etc.). This form of African currency also became known as 'slave trade money' after the Europeans started using them to acquire slaves for the slave trade into the Americas.