Queen Elizabeth II Dies at 96

King Charles was in Scotland with his family and was expected to return to London after spending the night in Balmoral. “The Queen died peacefully at Balmoral this afternoon,” Buckingham Palace said in a statement.

The queen’s death marks a watershed moment for the U.K. Britons under the age of 70 have grown up knowing only one monarch. She was the most visible link to the country’s imperial past and the embodiment of national identity. “We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother,” said King Charles III in a statement. “I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world.”

For the U.K., the queen’s death adds to a growing feeling of gloom at a time of high inflation, a looming recession, falling real wages and skyrocketing energy prices from the war in Ukraine.

Within minutes of the news, crowds gathered outside Buckingham Palace. Many hoisted cameras and phones in the air. In one corner of the crowd, some people sang “God Save the Queen.” Palace staff dressed in black posted the official notice of her death at the palace gates.

“We are all devastated,” British Prime Minister Liz Truss said. Queen Elizabeth was “the rock on which modern Britain was built,” she added.

Tributes poured in from world leaders. President Biden hailed the late queen as “the first British monarch to whom people all around the world could feel a personal and immediate connection.”

The House of Windsor is the last European monarchy to continue the practice of coronation. Marking her departure and the anointment of her successor will be critical to that transition and to maintaining the pageantry vital to sustaining the monarchy’s role and power. The new king is expected to be in London on Friday to swear an oath. He is also expected to tour the country to mark his mother’s passing.

Queen Elizabeth II’s historic reign spanned a period of deep social and economic change, from a nation of empire that pioneered globalization to a country that chose to pull out of the European Union, from a society with rigid class divisions to a diverse and more equal country.

“There will never be another monarch like her,” said Sarah Bunting, a child care professional who lives in west London. “She has been a rock for so many years and millions of people throughout the United Kingdom and the world will miss her.”

Britain will begin a 10-day mourning period on Friday that will culminate in Queen Elizabeth’s state funeral. Within minutes of the announcement of her death, the British Broadcasting Corp. went dark and played the national anthem. Flags on government buildings were lowered to half-staff. The government’s website featured a black banner to commemorate her passing.

Given the queen died in Scotland, she is expected to lie in state there before her body is moved to London for a state funeral in Westminster Abbey.

The British prime minister was informed of the queen’s death two hours before the news was announced.

During her last year of life, the queen was dogged by ill health and used a cane to get around, gradually reducing in-person meetings, especially after the passing of her husband Prince Philip in 2021. Even so, she kept up her constitutional duties. On Tuesday, she appointed Ms. Truss during a meeting at Balmoral.

While Britons had braced for the queen’s death, her demise came quickly. At around noon London time, minutes before palace officials released a statement saying doctors were concerned about her health, British politicians were passed notes in the House of Commons. As word spread, lawmakers asked each other to borrow black ties.

As news of the queen’s ill health circulated, crowds began gathering outside Buckingham Palace and people across the country started checking their phones for news.

“I have been on this earth since 1975 and she has just always been there,” said Karl Weeks, a 47-year-old from east London.

The queen was born in 1926 and her life stretched from the Roaring 20s through World War II, the Cold War, the collapse of communism, the rise of the internet and China and finally a return of war to Europe with Russia’s invasion of Ukraine.

Her reign spanned 15 prime ministers and 14 U.S. presidents, starting with Harry Truman. Despite the crumbling of the empire during her reign, her popularity endured and she remained the head of state of 15 countries.

“She was the last real European monarch, the last link to the world of the Romanovs, the Habsburgs, and probably the last European monarch to be revered. I don’t think there will be another one again,” said Ben Judah, a senior fellow at the Atlantic Council in London.

“It’s hard to explain the depth of connection between the British and the queen,” he said. “She’s on our coins, our stamps, she was the face of our diplomacy for as long as anyone remembers. She appeared at key moments on Christmas Day and sporting events. She’s almost a spiritual grandmother that transcends politics and class.”

—Caitlin McCabe contributed to this article.

Write to Max Colchester at max.colchester@wsj.com and David Luhnow at david.luhnow@wsj.com