Piers Morgan Champions Prince Philip's 'Selfless Public Duty'

Prince Philip, Queen Elizabeth's husband, has died at the age of 99, sending Britain into mourning and prompting tributes from around the world.

Broadcaster Piers Morgan said it was a "sad day for Britain" as he praised the "selfless" Duke of Edinburgh.

"RIP Prince Philip, 99," the former CNN host tweeted on Friday.

"A truly great Briton who dedicated his life to selfless public duty & was an absolute rock of devoted support to Her Majesty, The Queen, as the longest-serving royal consort to any British sovereign.

"A very sad day for our country. Thank you, Sir."

Prince Philip died peacefully on Friday, Buckingham Palace confirmed in a statement.

The statement read: "It is with deep sorrow that Her Majesty The Queen has announced 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."

Morgan has long been an ardent supporter of the royal family. He made headlines in recent weeks for publicly quitting his job on British breakfast T.V. because of comments he made about Meghan Markle following the Duke and Duchess of Sussex's bombshell interview with Oprah Winfrey.

After Prince Harry and Meghan's interview, he also tweeted: "This interview is an absolutely disgraceful betrayal of the Queen and the Royal Family. I expect all this vile destructive self-serving nonsense from Meghan Markle—but for Harry to let her take down his family and the Monarchy like this is shameful."

Earlier this week, the journalist and TV host said he had received messages "on behalf of several members of the royal family," thanking him for "standing up" to Meghan and Harry.

Politicians, world leaders and celebrities have sent messages of condolence to the royal family.

The U.K.'s prime minister Boris Johnson paid tribute to the Duke of Edinburgh with an impromptu speech outside No. 10 Downing Street on Friday afternoon.

Johnson praised Philip's "steadfast support for Her Majesty the Queen... her strength and stay for more than 70 years."

He said: "[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."

Johnson added: "So we mourn today with Her Majesty the Queen, we offer our condolences to her and to all her family and we give thanks, as a nation and a kingdom, for the extraordinary life and work of Prince Philip, Duke of Edinburgh."