Tributes came in from around the world on Friday after the death of Queen Elizabeth II's husband, Prince Philip was announced. He was 99.

Buckingham Palace announced that Duke of Edinburgh "passed peacefully away" at Windsor Castle, the royal residence in Berkshire, where he and his wife Queen Elizabeth II had spent much of their time during the novel coronavirus pandemic.

"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," palace officials said in a statement. "Further announcements will be made in due course. The Royal Family join with people around the world in mourning his loss."

Leaders from around the world paid tribute to the prince, who was recently discharged from a month-long stay in hospital, caused by an infection and a heart issue.

British Prime Minister Boris Johnson said Prince Philip was a "much-loved and highly respected public figure", who championed several environmental, educational and charitable causes.

"We will remember the Duke for all this, and above all for his steadfast support for Her Majesty the Queen," Johnson said. "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."

Former prime ministers Theresa May, Tony Blair, John Major and David Cameron all paid their respects, with the latter saying that Prince Philip "showed true dedication to our country, with unstinting service stretching back to his courageous naval duty in the Second World War".

United States House of Representatives'  Speaker Nancy Pelosi said the US Congress "extends condolences over the passing of Prince Philip, whose life was distinguished by an inspiring ethic of dedicated service."

Russia's President Vladimir Putin said that the prince was "tied to many important events in the recent history of your country. He was rightly respected among the British public and bore international authority."

Ursula von der Leyen, President of the European Commission, extended her "sincere sympathy" to the "people of the United Kingdom on this very sad day".

Canada's Prime Minister Justin Trudeau said that "Prince Philip contributed so much to the social fabric of our country, and the world".

India's Prime Minister Narendra Modi noted his "distinguished career in the military".

Scotland's First Minister Nicola Sturgeon said she was saddened by the news, and sent her "personal and deepest condolences" to the royal family, while the Prime Minister of Australia Scott Morrison said Prince Philip "embodied a generation that we will never see again".

Heads of state from Belgium, Sweden, Ireland, Latvia, Lithuania, Malta and Israel were among others to release statements on Friday afternoon, as did numerous political figures in the UK, including London Mayor Sadiq Khan and Labour Party leader Keir Starmer.

Tributes also came in from beyond the world of politics. Sports personalities Gary Lineker and Jose Mourinho both paid their respects on social media, the Archbishop of Canterbury Justin Welby gave tribute in a statement, as did British screenwriter Peter Morgan, who continues to chronicle the lives of the royal family in popular Netflix television series The Crown.

Parliament has already begun making arrangements to mark the passing of the prince. Senior government ministers scheduled a Cabinet meeting on Friday afternoon to pay tribute, and the House of Commons is being recalled on Monday, a day early from Easter recess, for tributes from MPs.

Arrangements for the funeral are likely to be impacted by the COVID-19 pandemic. When a member of the royal family dies, plans are laid out in code-named operations, in this case called Operation Forth Bridge. These plans provide meticulous mourning protocols from the local level all the way up to Parliament.

Operation Forth Bridge was under constant review, and adjustments will have been made to take into account certain lockdown and social distancing measures still in place in the UK.

Prince Philip is entitled to a full state funeral, which in normal times might involve thousands of members of the public gathering for a funeral procession through London, ending at Westminster Abbey, where several past monarchs and prime ministers have had memorials and a number of British luminaries including Charles Darwin, Charles Dickens, and Isaac Newton, are buried.

Such a public procession is unlikely to occur during the pandemic, however, and it is understood Prince Philip favored a more discreet, private service at St George's Chapel, Windsor, in the style of a military funeral, which could be televised.