For approximately 2,000 years, Swahili merchants have acted as middlemen between eastern and central Africa and the outside world. They played a significant role in the trade of ivory and enslaved peoples which climaxed during the 19th centuries. Trade routes extended across Tanzania into modern day Zaire, along which goods were brought to the coasts and were sold to Arab, Indian, and Portuguese traders. Many slaves sold in Zanzibar ended up in Brazil, which was then a Portuguese colony. Swahili fishermen still rely on the ocean to supply their primary source of income.
Fish is sold to their inland neighbors in exchange for products of the interior.
It is difficult to outline a Swahili political system, since they often incorporated the political practices of their neighbors. They are largely Islamic, and as such much of the power within the family rests in the hands of elder male members. Various Swahili empires have existed throughout history. Strongholds included communities centered in Mombassa, Lamu, and Zanzibar. Swahili traders also acted as middlemen between colonial governments and inland ethnic groups.