The peer who organised the Queen's funeral has been banned from driving for six months, despite claiming he needed his licence to arrange the King's upcoming coronation.
Edward Fitzalan-Howard, the 18th Duke of Norfolk, was caught using his mobile phone while driving in Battersea, south-west London, on 7 April.
He admitted the offence, at Lavender Hill Magistrates' Court earlier.
He had hoped to avoid a ban by claiming "exceptional hardship".
The Earl Marshal, 65, was stopped by police after his BMW cut across the officers' car, going through a red light, the court was told.
The officers drove up to his car and saw he was using his mobile phone. He told the officers he was "in communication with his wife", prosecutor Jonathan Bryan said.
Mr Bryan told magistrates the highest-ranking duke in England already had nine penalty points on his driving licence due to previous speeding offences and a compulsory endorsement of a further six points, which would lead to a ban.