The news spread quickly across the globe.

"Queen Elizabeth, the U.K.'s longest serving monarch, has died."

From the U.S. and the Bahamas...

"The Palace has just issued this statement: it says 'the Queen died peacefully at Balmoral this afternoon."

to the U.K....

"Prince Charles becomes immediately King Charles. The King of England. The King of Canada, by the way."

...and Canada.

Newscasters bid their goodbye to Queen Elizabeth II. For the vast majority of her subjects, she is the only monarch they have ever known.

She outlived the political lives of 15 Prime Ministers, appointing her final one - Liz Truss, who was born 101 years after her first appointee, Winston Churchill - just this week.

In one of her first tasks as the U.K.'s new leader, Truss consoled a nation in mourning.

"Through thick and thin, Queen Elizabeth II provided us with the stability and the strength that we needed. She was the very spirit of Great Britain and that spirit will endure."

Across the Atlantic, Canadian Prime Minister Justin Trudeau spoke highly of a woman he's known since his father, former Prime Minister Pierre Elliott Trudeau, led the commonwealth country. Canada is among the 15 commonwealth nations the Queen led.

"She was one of my favorite people in the world and I will miss her so."

A sombre open at the New York Stock Exchange as the U.S. paid their respects.

News of the Queen's passing broke during a White House press briefing.

Press Secretary Karine Jean-Pierre:

"The United Kingdom is one of our closest allies, and again our hearts go to the people of the United Kingdom, to the Queen, and to her family."

From one royal to another, Spain's King Felipe offered his condolences to the British royal family.

"Queen Elizabeth will be remembered as one of the best queens of all time due to her dignity, sense of duty, courage and her commitment to her people always and at all times. The United Kingdom and the world is in mourning."

Londoners young and old paid their tributes shortly after news broke outside Buckingham Palace.

"There will never be anybody like her again ever again that will serve for so long"

"Just can't really believe it to be honest because she's been queen my whole life."

As the world says goodbye, the reality of a new monarch - King Charles the III - is coming into focus.

At 73, he is the oldest to ever accede to the throne.

Historian Matthew Denison called this moment "cataclysmic."

"It's a change that very few people in this country will have experienced in their lives. And it is a cliche to say that the queen has been, you know, the still point, the vortex of modern life for 70 years. But that's absolutely true."