The former duke, who was stripped of his royal titles by the King last year but remains in the line of succession, has become the most senior member of the royal family in modern times to be arrested in an unprecedented development for the House of Windsor.
King Charles I was imprisoned by Oliver Cromwell nearly 380 years ago during the civil war and put under house arrest at Hampton Court Palace in 1647.
Former BBC royal correspondent Peter Hunt said the royal family was facing a situation that it was “ill-equipped to navigate”.
The King and Queen followed by the then-Duke of York on their way to church on Easter Sunday in 2023 (Yui Mok/PA)
Mr Hunt told the Press Association: “The arrest of the eighth in line to the British throne is seismic.
“Senior royals are now in uncharted waters that they are ill-equipped to navigate.
“They will have to answer questions about Andrew Mountbatten-Windsor and be held accountable, something which, up until now, has been an alien concept for them.”
The King issued a written statement following the arrest of his younger brother on Thursday over allegations of misconduct in public office.
The monarch, who did not receive advance warning of the arrest, said “the law must take its course” and expressed his “deepest concern” about the claims.
Andrew next to the Prince of Wales at the Duchess of Kent’s funeral in September (Jordan Pettitt/PA)
“What now follows is the full, fair and proper process by which this issue is investigated in the appropriate manner and by the appropriate authorities,” the King said.
“In this, as I have said before, they have our full and wholehearted support and co-operation.
“Let me state clearly: the law must take its course.”
He added: “As this process continues, it would not be right for me to comment further on this matter. Meanwhile, my family and I will continue in our duty and service to you all.”
Andrew attended the King’s coronation in 2023, but was eventually stripped of his prince and Duke of York titles by the monarch in 2025.
The then-Duke of York at Westminster Abbey following the King’s coronation in 2023 (Toby Melville/PA)
The banishment followed years of scandal over Andrew’s association with convicted sex offender Jeffrey Epstein, which first emerged a decade-and-a-half ago.
In 2002, Andrew’s sister the Princess Royal, who was then also eighth in line, was summoned to appear before magistrates after being prosecuted for keeping a dangerous dog when her English bull terrier dog Dotty bit two boys in Windsor Great Park.
It is not thought she was ever arrested.
Dotty apparently became over-excited when facing a bicycle and attacked the children, who were cousins, as they cycled through the parkland on Easter weekend.
Anne and her husband, the then-Commander Tim Laurence, leave East Berkshire Magistrates’ Court in Slough, after she admitted a charge under the Dangerous Dogs Act in 2002 (Toby Melville/PA)
It left them traumatised and suffering nightmares.
Anne and husband the then-Commodore Timothy Laurence were interviewed by Thames Valley Police at their Gatcombe Park home.
They were summonsed under Section 3 (1) of the Dangerous Dogs Act 1991 and were alleged to have been in charge of a dog that was dangerously out of control in a public place and injured the children.
Anne – daughter of the late Queen and Prince Philip – pleaded guilty to the charge and was fined £500 and ordered to pay £250 in compensation and £148 in costs after appearing at East Berkshire Magistrates’ Court in Slough.
In 2019, Philip came under police scrutiny when he crashed his Land Rover at the age of 97, hitting a car carrying a mother and a baby.
The Duke of Edinburgh was not prosecuted over his 2019 car crash (Steve Parsons/PA)
The Freelander Philip was driving was hit by another vehicle when he pulled out of a driveway on the Sandringham Estate in Norfolk on to a busy A road, after being dazzled by the low sun.
The duke’s car flipped over and he was trapped, and had to be rescued through the sunroof by a passing motorist.
The other vehicle, a Kia, was carrying a nine-month-old baby boy, his mother who was driving, and another woman, Emma Fairweather.
The baby was unhurt, but both women had to be treated in hospital, and passenger Ms Fairweather, who broke her wrist, called for Philip to be prosecuted if found to be at fault.
Broken glass and car parts on the side of the A149 near to the Sandringham Estate where the Duke of Edinburgh was involved in a road accident in 2019 (John Stillwell/PA)
Norfolk Constabulary said the incident would be “investigated and any appropriate action taken”, but Philip was not arrested.
A file on the investigation was passed to the Crown Prosecution Service (CPS), which, five days later, announced that Philip would face no further action.
Chris Long, chief crown prosecutor for CPS East of England, said the level of culpability, the duke’s age and his surrender of his driving licence had been taken into account, and it had been decided it was not in the public interest to prosecute.
In 2004, the late Queen’s usually dependable first cousin, the Duke of Gloucester, appeared before magistrates in Ely, Cambridgeshire, and was banned from driving for six months after admitting his fourth speeding offence in three years.
The Duke of Gloucester, who was president of the Institute of Advanced Motorists, was banned from driving for six months after being convicted of speeding in 2004 (Chris Radburn/PA)
He was fined £60 and ordered to pay £35 costs.
The duke, who had not been arrested, resigned from his role as president of the Institute of Advanced Motorists.