 Rather than being derived from the king creating his own chiefs (a tradition which, as we have seen, is of a relatively recent origin), they are instead derived from the high chiefs and district heads' direct descent from the founding fathers of the kingdom.Bonny became important in the 15th century with the arrival of the Portuguese and the growth of the Atlantic slave trade.At its height of power, Bonny was one of the main entrepôts on the Slave Coast.