21 December 1964
Most historians consider the first half of the 1960s as a period in which the Nationalist Party (NP) Government consolidated white rule in the face of growing international pressure and condemnation. The events of Sharpville massacre of 1960, and the subsequent State of Emergency followed by the banning of the ANC and PAC cast the South African government in a bad light in most of the western world. This led to the expulsion of South Africa from membership of many International bodies, particularly in sports and recreational activities. However, some Western governments, notably the British and US governments maintained good relations with the South African government. Some historians suggest that the relations between South Africa and Britain remained cordial because of extensive British investments in South Africa. The fact that Britain and the US always opposed any International censure against the Apartheid government encouraged South Africa to want to maintain good relations with the UK. The 1960s were marked by a growth in South Africa Manufacturing and Secondary Industry. The sector that realised marked growth was the Defence Industry, with major partners being Britain, the US, Germany and to a lesser extent France. The British agreement with South Africa came only three years after the country declared a republic, and ceased to be a member of the Commonwealth of Nations. During the first half of the 1960s and throughout the 1970s Britain maintained good relations with South Africa. South Africa was considered a strategic partner at the height of the Cold War. With the spectre of Marxist-backed Nationalist Movements threatening white rule in Rhodesia, South Africa and South West Africa, Western powers were particularly concerned about the fate of South Africa. This explains the British government's resolve to help South Africa strengthen its military capacity.
References

Giliomee, H and Mbenga, B. (eds) (2007) New History of South Africa, (Cape Town)|Thompson, L. A. (1992) History of South Africa  (Cape Town)|South Africa consolidating Apartheid [online] Available at: www.mongabay.com [Accessed on 15 December 2010]