evidence: Lake Malawi (Nyasa) – History, Wildlife, Geography, Borders and More Lake Malawi (previously known as Lake Nyasa or calendar lake malawi) is one of the African Great Lakes. It is located between Tanzania, Malawi, and Mozambique. It is the southernmost lake in the East African Rift (EAR) system. The lake is also called Lake Nyasa and Lago Niassa in Tanzania and Mozambique, respectively. [...] The division of the surface area of Lake Malawi between Tanzania and Malawi is disputed. Malawi lays claim to the entire surface of the lake not located in Mozambique. Their claim includes the waters next to Tanzania’s shoreline. On the other hand, Tanzania claims that the international boundary runs through the middle of Lake Malawi. Both countries quote the 1890 Heligoland Treaty between Germany and Great Britain as proof. The dispute started when the British colonial administration, immediately after capturing Tanganyika from the Germans, put all of the lake’s waters under one jurisdiction (the Nyasaland territory), without a distinct administration for the Tanganyikan part of the lake. Two jurisdictions were later created in colonial times.