Prince Andrew has renounced his military affiliations and royal patronages, Buckingham Palace says.
The move comes after Andrew's lawyers failed to persuade a US judge to dismiss a civil lawsuit against him that accuses him of sexual abuse.
"With The Queen's approval and agreement, The Duke of York's military affiliations and Royal patronages have been returned to The Queen," Buckingham Palace said in a statement.
"The Duke of York will continue not to undertake any public duties and is defending this case as a private citizen."
A royal source said Andrew would no longer use the title "His Royal Highness" in any official capacity and his other roles would be distributed among other members of the royal family.
They would not return to Prince Andrew.
The move represents the duke's complete removal from official royal life, and an attempt to distance the royal family from Andrew, who was once second in line to the throne as the spare to the heir, in the year of the Queen's Platinum Jubilee.
The development is a major blow for Prince Andrew, who is facing a court showdown after a judge ruled on Wednesday that Virginia Giuffre's lawsuit against him could go ahead.
"The Duke of York will continue not to undertake any public duties and is defending this case as a private citizen," Buckingham Palace said on Thursday.
A royal source said the issue had been widely discussed with the royal family, making it likely that Prince Charles - as well as Andrew - was involved in crisis talks over the matter.
The decision to remove the duke's military roles and royal patronages will have been a difficult one for the Queen for a son who denies the allegations against him.
It comes after more than 150 veterans joined forces to express their outrage, writing to the Queen to demand Andrew was removed from the honorary military positions.
Accusing the duke of bringing the services he is associated with into disrepute, the 152 former members of the royal navy, RAF and army said that "were this any other senior military officer it is inconceivable that he would still be in post".
The Queen is head of the armed forces and honorary military appointments are in her gift.
The Palace said previously that the duke's military appointments were in abeyance after he stepped down from public duties in 2019.
But until now he still retained the roles, which left the eight British regiments, including the Grenadier Guards of which he was Colonel, in limbo more than two years on.
Giuffre is suing the duke in the US for allegedly sexually assaulting her when she was a teenager.
The duke has strenuously denied the allegations.
A source close to the duke said he would "continue to defend himself" against Giuffre's allegations following the judge's decision to dismiss his legal team's attempt to have the case thrown out.
The source said: "Given the robustness with which Judge Kaplan greeted our arguments, we are unsurprised by the ruling.
"However, it was not a judgment on the merits of Ms Giuffre's allegations. This is a marathon not a sprint and the duke will continue to defend himself against these claims."
with reporting from PA
Australian Associated Press
