Query: What nationality were the first navigators to explore Namibia come from? 
Context: The first Europeans to disembark and explore the region were the Portuguese navigators Diogo Cão in 1485 and Bartolomeu Dias in 1486; still the region was not claimed by the Portuguese crown. However, like most of Sub-Saharan Africa, Namibia was not extensively explored by Europeans until the 19th century, when traders and settlers arrived, principally from Germany and Sweden.