Portuguese language in Africa as a second language, in countries like Angola and Mozambique, where Portuguese is an official language, but also in countries like South Africa and Senegal, thanks to migrants coming from Portuguese speaking countries. Some statistics claim that there are over 30 million Portuguese speakers in the continent. Like French and English, Portuguese has become a post-colonial language in Africa and one of the working languages of the African Union (AU) and the Southern African Development Community (SADC). Portuguese co-exists in Guinea-Bissau, Cape Verde, and São Tomé and Principe with Portuguese-based creoles (Upper Guinea and Gulf of Guinea Creoles), and in
South West Africa which were united with the rest of the country in 1994. As a German colony from 1884, it was known as German South West Africa ("Deutsch-Südwestafrika"). Germany had a difficult time administering the territory, which experienced many insurrections, especially those led by guerilla leader Jacob Morenga. The main port, Walvis Bay, and the Penguin Islands were annexed by the UK in 1878, becoming part of the Cape Colony in 1884. Following the creation of the Union of South Africa in 1910, Walvis Bay became part of the Cape Province. As part of the Heligoland-Zanzibar Treaty in 1890, a corridor of