In 1976, Transkei was proclaimed by the apartheid-era South Africa as an "independent black homeland" (in actuality, an area set up to reduce the black population of South Africa by giving them citizenship in this new area.) Not internationally recognized, Transkei was re-incorporated into South Africa when the apartheid system was abolished in 1994.
As a separate "nation", Transkei adopted the famous southern African song "Nkosi sikelel' iAfrika" as its official national anthem. In fact, the song was written and composed in what later became Transkei; as well, the writer of the song, Enoch Sontonga, was a member of the Xhosa people, which was the official language of Transkei. Interestingly, not only was "Nkosi sikelel' iAfrika" used for decades prior to the creation of Transkei as the anthem of the anti-apartheid movement, but also, this song became part of the anthem of the new South Africa after Transkei was re-integrated.
This is a very popular song with the blacks of southern Africa, as not only has it served as the anthem of other southern African states (such as Tanzania, Zambia, and Zimbabwe (from 1980-1994)) but also other black "homelands" adopted this anthem such as Ciskei (which also was awarded "independence"), KwaZulu, Lebowa, QwaQwa, Ganzankulu, KaNgwane and KwaNdebele (although these others, with the exception of Transkei (whose official language was also Xhosa), probably used translations into their own language.) There is also no standard version or translation for "Nkosi sikelel' iAfrika", it may vary from place to place and occasion to occasion, and I believe no official version was adopted in Transkei.