Portuguese language in Africa more recent migrations of refugees (some of whom speak Portuguese) to neighbouring countries such as Democratic Republic of Congo, Namibia, Zambia and South Africa. Other migrations involved returning Afro-Brazilian ex-slaves to places such as Nigeria, Benin, Togo, Angola and Mozambique. There are also some returning white Portuguese African refugees and their descendants from Brazil, Portugal, and South Africa to their former African controlled territories, mostly to Angola (up to 500,000) and Mozambique (350,000), and most importantly, there is the arrival of Portuguese post-colonial expatriates in Angola in the recent years, because of Portugal's economic interests and the Angolan economic boom.
West Africa various ethnic groups. For historical reasons, Western European languages such as French, English and Portuguese predominate in Southern and Coastal subregions, whilst Arabic spreads inland northwards. The Economic Community of West African States (ECOWAS), founded by the 1975 Treaty of Lagos, is an organization of West African states which aims to promote the region's economy. The West African Monetary Union (or UEMOA from its name in French, "Union économique et monétaire ouest-africaine") is limited to the eight, mostly Francophone countries that employ the CFA franc as their common currency. The Liptako-Gourma Authority of Mali, Niger, and Burkina Faso seeks to