Queen Elizabeth II's husband Prince Philip dies aged 99

"It is with deep sorrow that Her Majesty The Queen announces the death of her beloved husband, His Royal Highness The Prince Philip, Duke of Edinburgh," it said in a statement.

"His Royal Highness passed away peacefully this morning at Windsor Castle.

"The Royal Family join with people around the world in mourning his loss."  

The palace added that further announcements would be made "in due course".

Fears over the health of the Duke of Edinburgh, as he was formally known, had been heightened after he recently spent a month in hospital for treatment.

He left hospital on March 16 following what was described as a successful procedure for a pre-existing condition and treatment for an unspecified infection.

He was first admitted on February 16 on the advice of his doctor after he complained of feeling unwell. 

Philip had returned to Windsor Castle, west of London, where he had been isolating with the queen -- Britain's longest-serving monarch -- since the start of the coronavirus pandemic last year.

He was due to turn 100 in June.

The news of his death saw television channels interrupt regular programmes and start special coverage marking his life.

The BBC announced his death and played the national anthem, "God Save the Queen".

Philip had increasingly struggled with his health in recent years, and had retired from public life.

In the run-up to Christmas 2011, Philip was taken to hospital by helicopter after suffering chest pains. 

The Greek-born former naval officer was then treated for a blocked coronary artery and had a stent fitted.