A review is given of the development of systems of photometric standard stars at the South African Astronomical Observatory. A brief historical perspective indicates how the Harvard E-regions were chosen as standard sequences and developed into a very precise Southern hemisphere system for UBV(RI) c photometry. Subsequent additions of Stromgrenuvby - Hβ and DDO photometry to samples of E-region stars and UBV(RI) c extensions to the F-regions and the Magellanic Clouds are also described. Current programmes to extend and improve these standard stars are briefly discussed, as well as the long-standing problem of linking the Northern and Southern systems.