In one version of Siyahamba's history, it was originally composed as an Afrikaans hymn in around 1950 by Andries van Tonder, an elder of the Dutch Reformed Church; the song was then later translated into Zulu by a Thabo Mkize.
In an alternative and apparently well-researched version of events, it originated with Amadodana, a South African Methodist young men's group, as a Zulu freedom song made up against a background of apartheid political oppression.
Either way, it appears to owe its more widespread popularity to Anders Nyberg, the director of a Swedish choir who toured South Africa in 1978. He heard and recorded the song at a girl's school in Natal, and later published his own four-part arrangement in an anthology of South African freedom songs. Since then it has been translated into many languages, and is particularly popular with children's choirs.
The video to the right has the song performed a capella by the Croatian choir Rondo Histriae, with verses in both Zulu and English.
Sadly, performances of the fabled Afrikaans version seem impossible to find. Nonetheless, the Gurt Lush arrangement tries to reflect a sober Protestant musical approach in its opening section, before moving into a more African ethnic mode for the rest of the song.
The commonly-sung (but variously-spelt) Zulu words, Siyahamb' ekukhanyeni kwenkhos, mean We are marching in the light of God. Gurt Lush's version has a second verse, transcribed phonetically from this "field recording" of a chaotic impromptu performance on a Kenyan hilltop. It's quite likely a Swahili version of the same words - Natembea apparently means I am walking.
Here are a few other versions from the thousands that YouTube has to offer: