Mr Buthelezi's response will determine whether his supporters resume hostilities against Nelson Mandela's African National Congress, initiating a new era of violence after five months of peace since April's elections.
The king's decision to strip Mr Buthelezi, his uncle, of his cherished position as 'traditional prime minister' to the Zulu monarchy came on a day when John Major addressed the South African parliament - the first British prime minister to visit the country since Harold Macmillan made his 'Wind of Change' speech here, 34 years ago.
By weakening his uncle's hold on the loyalty of conservative Zulus, the king has revived the spectre of political instability that appeared to have been banished by Nelson Mandela's peaceful ascent to power. The war between Inkatha and ANC Zulus claimed more than 10,000 lives in KwaZulu-Natal alone between the mid-Eighties and the elections.
In a statement, the king announced that because of tensions in the Zulu kingdom, a rally planned for Saturday to commemorate Shaka, legendary founder of the Zulu nation, would be called off. The statement added bluntly: 'The King must not meet Buthelezi again.'
A medieval feud, page 14