Britain's Queen Elizabeth II, one of the world's longest-serving monarchs and revered around the globe, died Thursday, Buckingham Palace said. She was 96.

"The Queen died peacefully at Balmoral this afternoon," the palace said. The queen was vacationing at the castle in Scotland.

Prince Charles, 73, the first son of the queen and her deceased husband Prince Philip, immediately became King Charles III.

The new king said in a statement, "During this period of mourning and change, my family and I will be comforted and sustained by our knowledge of the respect and deep affection in which The Queen was so widely held."

File photo shows Britain's Queen Elizabeth II attending a reception at Sandringham Estate in England in February, 2022. (Getty/Kyodo)

As well as being the figurehead for the United Kingdom, she was the sovereign in 14 other countries, including Australia and Canada. The queen was also the head of the Commonwealth, a voluntary association of 56 countries, of which 15, including Britain, have the queen as head of state.

British Prime Minister Liz Truss said, "Through thick and thin, Queen Elizabeth II provided us with the stability and the strength that we needed."

"Throughout her life she has visited more than 100 countries and she has touched the lives of millions around the world," she said.

The queen maintained good relations with the Japanese imperial family and several reciprocal visits during her reign helped repair the damage done by World War II.

Japanese Prime Minister Fumio Kishida said Friday the queen contributed to cementing bilateral relations, noting her visit to the country in 1975, the first by a British monarch.

"She played a significant role in creating world peace and prosperity," Kishida told reporters at his office, adding the queen's death was a "big loss" to the international community.

On Sept. 9, 2015, Queen Elizabeth surpassed Queen Victoria's record, becoming Britain's longest-reigning monarch. On Feb. 6, 2022, she marked 70 years on the throne.

According to The Times, she was the world's second-longest reigning monarch of a sovereign state, only having been surpassed by Louis XIV of France, who ruled for 72 years and 110 days from 1643 to 1715.

Tributes are laid outside of Windsor Castle on Sept. 8, 2022, in Windsor, England. (Getty/Kyodo)

She was born in London on April 21, 1926, and christened Elizabeth Alexandra Mary.

At the time, there was little expectation that then Princess Elizabeth, who was schooled at home, would become a future queen as she was third in line to the throne.

However, in December 1936, her uncle, King Edward VIII, abdicated to marry the divorcee Wallis Simpson, and the princess's father became King George VI.

The family -- King George, Queen Elizabeth, Princess Elizabeth and Princess Margaret -- all lived in Buckingham Palace, central London.

In World War II, the family remained in Britain and acted as a beacon of national unity and solidarity during the dark days.

In 1940, 14-year-old Princess Elizabeth made her first radio broadcast -- to the nation's children -- and later, in 1945, she trained as a driver and mechanic to help the war effort.

Following the war, the nation was cheered when it was announced in July 1947 that the princess was to marry the dashing naval officer Philip Mountbatten, who was distantly related to the princess through Queen Victoria and a descendant of several European royal families.

Princess Elizabeth and her husband, Prince Philip, Duke of Edinburgh, married on Nov. 20, 1947, in Westminster Abbey. Their first child, Prince Charles, was born in 1948. They went on to have one daughter, Princess Anne, in 1950 and two more sons, Prince Andrew and Prince Edward, in the 1960s.

The young couple enjoyed a relatively normal married life for a few years when Prince Philip was working in Malta between 1949 and 1951.

However, that relative normality ended for Princess Elizabeth on Feb. 6, 1952, when her father died while she was in Kenya, and she learned that she was now queen.

Her coronation took place on June 2, 1953, and was the first such event to be televised.

Over the subsequent years and decades, the queen made good on the pledge she made to her subjects on her 21st birthday: she would devote her whole life to the service of the Commonwealth.

Her duties involved a never-ending stream of visits, receptions and ceremonies, in addition to state papers she needed to read and sign every day. By January 2017, the queen had visited 117 countries.

Britain's Queen Elizabeth II (R), who passed away on Sept. 8, 2022, is pictured with then Japanese Emperor Akihito (C) and then Empress Michiko at Buckingham Palace in London in May, 1998. (Kyodo)   

In May 1975, the queen met Emperor Hirohito, posthumously known as Emperor Showa, during her visit to Japan.

She attracted a TV audience of millions, and the Japanese were attracted by her "informal" style.

The queen also had good relations with former Emperor Akihito despite his visit to Britain in 1998 being dogged by protests from former POWs.

Although appearing rather formal and stiff, it was often said the queen took great delight when things did not go to plan or if protocol was breached.

And her more lighthearted side was on show to the world when she memorably starred alongside the James Bond actor Daniel Craig at the opening ceremony for the 2012 London Olympics.

She rarely expressed her emotions, although she notably described 1992 as her family's "annus horribilis" following the separation of Prince Charles and his wife Diana, Princess of Wales, and a fire that gutted parts of Windsor Castle that year.

Another of her biggest challenges came following the death of Diana in 1997 when the queen was criticized for initially refusing to allow the national flag to fly at half-staff over Buckingham Palace.

However, in some ways, the queen did modernize the British royal family. She allowed TV cameras into her various palaces to cover the workings of the monarchy, and in 1992 she agreed to pay taxes on her personal income.

Crowds gather in front of Buckingham Palace in London to pay their respects following the death of Queen Elizabeth II on Sept. 8, 2022. (Getty/Kyodo)

The queen always remained neutral and kept out of politics. However, during the 2014 Scottish independence referendum, she told a member of the public that she hoped people would think very carefully before voting. This was seen as an endorsement of the union, with then Prime Minister David Cameron later saying he had sought some subtle form of backing from the monarch.

Throughout her life, she remained extremely popular with the public, while other family members drew sharp criticisms for their behavior.

In her later life, one of her biggest challenges was Prince Andrew's former association with the disgraced U.S. financier Jeffrey Epstein. The prince, her second son, stepped down from public duties in November 2019, and in February 2022, he reached an out-of-court settlement with a woman who accused him of sexual assault. He denied all the allegations.

She was also forced to address the future role of her grandson Prince Harry and his wife, Meghan Markle, following acrimonious discussions that led to the couple also stepping back as senior royals in January 2020.

Also, in her later years, she reduced her workload, did not travel overseas and spent more time at Windsor Castle. During the coronavirus pandemic in 2020, she isolated herself with a small team and her husband. Despite the isolation, she embraced modern technology and often held virtual audiences via video conference.

Her biggest loss came in April 2021 when Prince Philip died aged 99, the longest-serving British consort and the man she famously described as her "strength and stay." Very poignantly, she had to sit alone in the chapel during his funeral due to social distancing guidelines during the pandemic.