Excerpts from Books and Wikipedia
"Yet on this day Macmillan delivered a speech to the South African Parliament that publicly challenged the Afrikaner regime. . . . Riots and a damning official report in 1959 had convinced Britain that Nyasaland (Malawi) and Northern Rhodesia (Zambia) should soon have black self-government. South Africa voluntarily left the Commonwealth in 1961 to avoid expulsion. Macmillan's speech was a somewhat belated recognition that things were changing rapidly in Africa." [Furtado: 1001 Days]