Beatrice, 31, had been due to marry Italian property developer Edoardo Mapelli Mozzi, 37, at St James's Palace in central London on May 29.

But the nuptials were on hold and no rescheduled date was given.

Buckingham Palace confirmed the couple tied the knot in an unannounced ceremony in front of her grandmother, Queen Elizabeth II, and a small number of guests.

"The private wedding ceremony of Princess Beatrice and Mr Edoardo Mapelli Mozzi took place at 11:00 am (1000 GMT) on Friday 17th July, at the Royal Chapel of All Saints at Royal Lodge, Windsor," the royal family said in a statement.

"The small ceremony was attended by the Queen, the Duke of Edinburgh (Prince Philip) and close family. The wedding took place in accordance with all relevant government guidelines."

The queen, 94, and her 99-year-old husband have been self-isolating at the castle west of London because their age puts them in a high-risk category for coronavirus.

Beatrice and her sister Eugenie, 30, are the daughters of Andrew and his ex-wife Sarah Ferguson. Both attended the ceremony, as did the groom's parents, reports said.

Andrew stepped back from frontline royal duties last year after he caused outrage in a television interview by defending his friendship with Jeffrey Epstein.

Epstein, a millionaire US financier, was found dead in prison last year as he awaited trial on sex trafficking charges.

Andrew, 60, has denied claims that he had sex with a 17-year-old girl trafficked by Epstein.

US investigators are keen to speak to the prince about his links to Epstein, after the arrest of British socialite Ghislaine Maxwell on sex trafficking charges.