No-one knows the origin of the name Niger. Many people think that it comes from the Latin word for "black", "niger", but there is no evidence for this, and Portuguese explorers would probably have used their own word ("negro") on their maps. Also, the Niger is not a blackwater river (see Rio Negro). Some people think that 'black' may mean the color of the people in this area, but this did not happen with any other river in Africa.