20 February 1950
The Population Registration Bill was read for the first time in Parliament. The Bill was a cornerstone of the Apartheid policy as it recognised three race classifications, namely Whites, Coloureds and Natives (Blacks). Indians were initially classified as Coloureds until a fourth racial group was added later. An office of race classification was set up to oversee the classification process. The Population Registration Act (No. 30 of 1950), promulgated on 7 July 1950, made the Group Areas, Immorality and Mixed Marriages Acts possible.
References

Conlon, P.J., (2006), South African Stories - One: The Population Registration Act, from South African Stories, 20 June [online], Available at southafricanstories.blogspot.com [Accessed: 30 January 2014]|Joyce, P. (1990). The Rise and Fall of Apartheid, Cape Town: Struik.|Potgieter, D.J. et al. (eds)(1970). Standard Encyclopaedia of Southern Africa, Cape Town: NASOU, v. 9, p. 10.