Informal male youth varieties are a widespread phenomenon of township life across South Africa. A common view is that there are two varieties with separate origins: a Bantu language-based variety, called Iscamtho, and an Afrikaans-based variety called Tsotsitaal that has decreased in use because of the unpopularity of Afrikaans. This article examines the origins and relationship between these two varieties by investigating the social history of Bantu- and Afrikaans-based varieties in two townships east of Johannesburg: Stirtonville (a mixed-race township) and its successor, Vosloorus, to where, Bantu languagespeaking Stirtonville residents were forcibly moved in 1964. Young men who were old enough to participate in male youth street social networks in Stirtonville mainly used an Afrikaans-based slang. When Stirtonville residents moved to Vosloorus, the grammatical base of the male youth variety shifted from Afrikaans to Zulu and South Sotho. These findings suggest that the Afrikaans and Bantu language-based youth varieties are not separate phenomena with different origins. Rather, they support more recent work on male youth communicative practices showing that these informal varieties are not separate languages, but manifestations of one phenomenon, a performative style of speaking among young men involving the insertion of a slang lexicon into a local language.