The queen, who was 96, died peacefully at Balmoral Castle, her home in the Scottish Highlands, according to Buckingham Palace. Her son, King Charles III, became the next ruler of the United Kingdom.
Here are some reactions to the news from current and previous international leaders:
People gathering outside Buckingham Palace on Thursday after the news of the queen’s death was announced.Credit...Andrew Testa for The New York Times
Singapore Prime Minister Lee Hsien Loong
"Her Majesty was the heart and soul of the United Kingdom. Her passing is greatly mourned by everyone in Singapore.
"Her Majesty also left a significant mark on Singapore's history and our longstanding close relations with the United Kingdom.
"Her Majesty's reign saw one of the longest periods of peace and prosperity in the history of the United Kingdom. Throughout her life, she steadfastly served the United Kingdom and the Commonwealth.
"Her contributions to the United Kingdom, the Commonwealth, and indeed to the world will be recorded in history, and she will always be remembered fondly as a great world leader."
Japanese Prime Minister Fumio Kishida
"I can't help but feel deep sorrow, and I offer my heartfelt condolences to the British Royal Family, government and people.
"The death of the Queen, who led Britain through turbulent times in the world, is a great loss not only for the British people but also the international community.”
Indian Prime Minister Narendra Modi
"Her Majesty Queen Elizabeth II will be remembered as a stalwart of our times. She provided inspiring leadership to her nation and people. She personified dignity and decency in public life. Pained by her demise. My thoughts are with her family and people of UK in this sad hour."
Prime Minister of Pakistan Shebaz Sharif
"Deeply grieved at the passing of Her Majesty Queen Elizabeth II. Pakistan joins the UK & other Commonwealth nations in mourning her death. My heartfelt condolences to the royal family, people & government of the UK."
New Zealand Prime Minister Jacinda Ardern
"I know that I speak for people across New Zealand in offering our deepest sympathy to members of the Royal Family at the passing of the Queen. To us she was a much admired and respected monarch, to them she was a mother and grandmother.
"The Queen was a much loved and admired monarch, whose record reign of 70 years is an absolute testament to her, and her commitment to us all. She was extraordinary."
People gathering outside Buckingham Palace on Thursday after the news of the queen’s death was announced.Credit...Andrew Testa for The New York Times
Australian Prime Minister Anthony Albanese
"With the passing of Queen Elizabeth the Second, an historic reign and a long life devoted to duty, family, faith and service has come to an end.
"Australian hearts go out to the people of the United Kingdom who mourn today, knowing they will feel they have lost part of what makes their nation whole.
"There is comfort to be found in Her Majesty's own words: 'Grief is the price we pay for love'."
UN Secretary-General Antonio Guterres
"As the United Kingdom's longest-lived and longest-reigning Head of State, Queen Elizabeth II was widely admired for her grace, dignity, and dedication around the world. She was a reassuring presence throughout decades of sweeping change, including the decolonization of Africa and Asia and the evolution of the Commonwealth.
"Queen Elizabeth II was a good friend of the United Nations, and visited our New York Headquarters twice, more than fifty years apart. She was deeply committed to many charitable and environmental causes and spoke movingly to delegates at the COP26 climate talks in Glasgow.
"I would like to pay tribute to Queen Elizabeth II for her unwavering, lifelong dedication to serving her people. The world will long remember her devotion and leadership."
US President Joe Biden and First Lady Jill Biden
"In a world of constant change, she was a steadying presence and a source of comfort and pride for generations of Britons, including many who have never known their country without her," they said in a statement. "Her legacy will loom large in the pages of British history, and in the story of our world."
Former US president Barack Obama and first lady Michelle Obama
'Michelle and I were lucky enough to come to know Her Majesty, and she meant a great deal to us.
'Back when we were beginning to navigate life as President and First Lady, she welcomed us to the world stage with open arms and extraordinary generosity.
'Time and again, we were struck by her warmth, the way she put people at ease, and how she brought her considerable humour and charm to moments of great pomp and circumstance.
'Like so many of you, Michelle and I are grateful to have witnessed Her Majesty’s dedicated leadership, and we are awed by her legacy of tireless, dignified public service.".
Prime Minister Liz Truss before speaking about the death of the queen on Thursday.Credit...Alberto Pezzali/Associated Press
Former US president Donald Trump and first lady Melania Trump
“Melania and I are deeply saddened to learn of the loss of Her Majesty Queen Elizabeth II.
"Queen Elizabeth’s historic and remarkable reign left a tremendous legacy of peace and prosperity for Great Britain. Her leadership and enduring diplomacy secured and advanced alliances with the United States and countries around the world.
“Melania and I will always cherish our time together with the Queen, and never forget Her Majesty’s generous friendship, great wisdom and wonderful sense of humor. What a grand and beautiful lady she was. There was nobody like her!”
A dignified and steady figure who reigned longer than any previous British queen, helped bring the institution into the contemporary world, removing court rituals and making it more open and accessible, all under the glare of an increasingly invasive and frequently unfriendly media.
While the country she ruled over struggled at times to find its position in a new world order, and her own family frequently failed to meet popular expectations, the queen herself remained a symbol of stability. She also attempted to break through class barriers, earning the reluctant admiration of even the most diehard Republicans.
"I think she's brought life, energy and passion to the job, she's managed to modernise and evolve the monarchy like no other," her grandson Prince William, who is now the heir to the throne, said in a television documentary in 2012.
'A huge shock to the country.'
The queen, whose husband died last year, has been suffering from "episodic mobility issues" since the end of last year, causing her to cancel practically all of her public appearances.
Queen Elizabeth greeting Liz Truss on Tuesday in Aberdeen, Scotland. The queen broke with the tradition of meeting the new prime minister at Buckingham Palace, after needing to remain at Balmoral Castle because of mobility issues.Credit...Pool photo by Jane Barlow
Her last formal act was to designate Truss as Prime Minister on Tuesday, the 15th of her rule.
"Her Majesty the Queen's passing is a profound shock to the nation and the globe," Truss said outside her Downing Street office, where the flag had been lowered, as had those at royal palaces and government buildings around the country.
“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,” said Truss, who was informed of the death at 4.30pm London time.
We mourn Her Majesty Queen Elizabeth II's passing. She committed her life to public service with dignity and commitment for more than seven decades, inspiring countless people throughout the world.
Sgfirstaid expresses its heartfelt condolences to the royal family and the people of the United Kingdom and the Commonwealth.
Queen Elizabeth II in 2018.Credit...Tim Ireland/Associated Press
Even near the end, in her declining state, the queen was a constant, revered figure in the public life of her country. During the depths of the pandemic, she addressed a socially isolated nation, assuring Britons, in the words of Vera Lynn’s beloved World War II-era song, that “We will meet again.”