South Africa's justice minister has thrown out a bid by the Thembu king to reopen his criminal trial so that he can avoid serving 12 years in prison.
King Buyelekhaya Dalindyebo had failed to provide any new evidence to justify a retrial, Michael Masutha said.
The monarch is due to report to prison on Wednesday after being convicted of kidnapping, assault and arson.
He comes from the Thembu clan, to which South Africa's first black president, Nelson Mandela, belonged.
King Dalindyebo is the first monarch to be convicted of a crime in South Africa since minority rule ended in 1994.
He ascended to the throne in 1989, and has about 700,000 subjects.
The late Mr Mandela grew up in the Thembu royal household, and was the 51-year-old King Dalindyebo's uncle.
South Africa has 10 officially recognised monarchs representing different ethnic groups and clans.
They play a largely ceremonial role, and attend to minor disputes within their communities.
The case against King Dalindyebo was related to a dispute he had with some of his subjects more than two decades ago.
He was accused of kidnapping a woman and her six children, setting their home on fire and beating up four youths, one of whom died, because one of their relatives had failed to present himself before the king's traditional court.
King Dalindyebo appealed to Mr Masutha to reopen his trial after failing in the courts to have his conviction and sentence set aside.
His legal team said he would not report to prison on Wednesday, as they intended to apply for his bail to be extended yet again, the national broadcaster, SABC, reports on its website.
Last week, a court extended King Dalindyebo's bail while Mr Masutha considered his request for a retrial, making it possible for him to spend Christmas at home.
Many people feel King Dalindyebo has disgraced the royal family, and that he will be hard-pressed to find any sympathy, correspondents say.
There is already talk of his son, Prince Azenethi Dalindyebo, being crowned as the next monarch.
King Dalindyebo was a member of the opposition Democratic Alliance (DA) party, but it revoked his membership following his conviction.
Sentencing him in October, the Supreme Court of Appeal said: "His behaviour was all the more deplorable because the victims of his reign of terror were the vulnerable rural poor, who were dependent upon him. Our constitution does not countenance such behaviour.
"We are a constitutional democracy in which everyone is accountable and where the most vulnerable are entitled to protection."