The British protectorate known as Nyasaland was Malawi.
Nyasaland was the name used for the British Nyasaland Protectorate in southeastern Africa. The protectorate was created in 1907 when the earlier British Central Africa Protectorate was renamed. Its territory broadly corresponds to modern Malawi, a landlocked country situated between Zambia, Tanzania, and Mozambique.
Nyasaland was administered directly by Britain until 1953, when it became part of the Federation of Rhodesia and Nyasaland alongside Northern Rhodesia and Southern Rhodesia. The federation was controversial, particularly because African political leaders opposed its racial and constitutional arrangements.
The federation dissolved at the end of 1963. Nyasaland achieved independence on 6 July 1964 and adopted the name Malawi. The older name is therefore historical rather than an alternative modern name for Tanzania, Zambia, or Zimbabwe. A useful distinction is that Northern Rhodesia became Zambia, Southern Rhodesia became Zimbabwe, and Nyasaland became Malawi.