The Bight of Benin (Republic of Benin)'s shore was part of the so-called "Slave Coast", from where many West Africans were sold (usually by local rulers) to foreign slave traders. In the early 16th century the Oba sent an ambassador to Lisbon, and the King of Portugal sent Christian missionaries to Benin. Some residents of Benin could still speak a pidgin Portuguese in the late 19th century. To preserve Benin's (of Nigeria) independence, bit by bit the Oba banned the export of goods from Benin, until the trade was exclusively in palm oil.