PRINCE Philip has died at the age of 99, Buckingham Palace has said. 

The Duke of Edinburgh, who was married to Queen Elizabeth II for more than 70 years, passed away this morning at Windsor Castle. 

He was the longest serving consort in British history and his death comes shortly after he spent an extended period of time in hospital.

READ MORE: Prince Philip: Glasgow pays tribute to Duke of Edinburgh after death

He officially retired from public engagements in the summer of 2017.

Glasgow Times:

A statement from the palace read: "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.

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

"Further announcements will made in due course.

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

Philip had returned to Windsor Castle on March 16 to be reunited with the Queen after spending a month in hospital – his longest ever stay.

He initially received care for an infection but then underwent heart surgery for a pre-existing condition.

READ MORE: Prince Philip dies aged 99 LIVE updates: Buckingham Palace lead tributes

The duke had looked gaunt as he was driven away from King Edward VII’s Hospital in central London, having been pushed in a wheelchair to the waiting car.

Philip – father to the Prince of Wales, the Princess Royal, the Duke of York and the Earl of Wessex – was just two months away from his 100th birthday in June.

He spent much of the Covid-19 crisis staying with the Queen at Windsor in HMS Bubble – the nickname given to the couple’s reduced household of devoted staff during lockdown.

Today Nicola Sturgeon was among those to pay tribute to Philip, writing:"I am saddened by news that the Duke of Edinburgh has died.

"I send my personal and deepest condolences - and those of the Scottish Government and the people of Scotland - to Her Majesty The Queen and her family." 

Prime Minister Boris Johnson said: "He (Philip) was an environmentalist, and a champion of the natural world long before it was fashionable.

“With his Duke of Edinburgh awards scheme he shaped and inspired the lives of countless young people and at literally tens of thousands of events he fostered their hopes and encouraged their ambitions.

“We remember the duke for all of this and above all for his steadfast support for Her Majesty the Queen.

Glasgow Times: A sign announcing the death of the Duke of Edinburgh, who has died at the age of 99, is placed on the gates of Buckingham Palace, London. (Ian West/PA)A sign announcing the death of the Duke of Edinburgh, who has died at the age of 99, is placed on the gates of Buckingham Palace, London. (Ian West/PA)

“Not just as her consort, by her side every day of her reign, but as her husband, her ‘strength and stay’, of more than 70 years.

“And it is to Her Majesty, and her family, that our nation’s thoughts must turn today.

“Because they have lost not just a much-loved and highly respected public figure, but a devoted husband and a proud and loving father, grandfather and, in recent years, great-grandfather.”