It was the days of pan africanism, the song was composed in 1847 by Enoch Satonga called Nkosi Sikeleli Africa, it was officially recorded in 1923 and was mainly an ANC anthem, Tanzania adopted the theme in 1961 and was the first to use it as its national anthem, followed by zambia and zimbabwe (zimbabwe changed its anthem in the 90s) , changing a few words but leaving the same context (God bless africa..)