Britain's longest reigning monarch Queen Elizabeth II dies at 96

The Queen reigned for 70 years.

The royal family including the Queen's son and heir Prince Charles, grandsons William and Harry and their families have gathered at her Balmoral retreat in the Scottish highlands, where she spent her last days.

The UK celebrated the Queen's Platinum Jubilee to mark 70 years of service to the country with gala events in June this year.

In 2015, Queen Elizabeth became the longest-serving British monarch, surpassing her great-great grandmother Queen Victoria. This year, she became the world's second longest reigning monarch.

The Queen had received Britain's newly elected Prime Minister Liz Truss at Balmoral Castle on Sept 6 and had officially asked her to form the government.

In a first, she appointed Liz Truss in Balmoral in Scotland as she was too ill to return to London to fulfill her official duties.

Reacting to the demise, Liz Truss tweeted: "The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime. My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time."

With the Queen's death, her eldest son and Prince of Wales-Charles became the new monarch.

Born in Mayfair, London, Queen Elizabeth II, was the first child of the Duke and Duchess of York (later King George VI and Queen Elizabeth). Her father acceded to the throne in 1936 upon the abdication of his brother, King Edward VIII, making Elizabeth the heir presumptive.

She was educated privately at home and began to undertake public duties during the Second World War, serving in the Auxiliary Territorial Service.

In November 1947, she married Philip Mountbatten, a former prince of Greece and Denmark, and their marriage lasted 73 years until his death in April 2021.

They had four children together: Charles, King of the United Kingdom; Anne, Princess Royal; Prince Andrew, Duke of York; and Prince Edward, Earl of Wessex.

At the age of 25, the Queen Elizabeth was helmed the responsibility of the Royal Kingdom and became queen regnant of seven independent Commonwealth countries: the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan, and Ceylon (known today as Sri Lanka), as well as Head of the Commonwealth.

She reigned as a constitutional monarch through major political changes such as the Troubles in Northern Ireland, devolution in the United Kingdom, the decolonisation of Africa, and the United Kingdom's accession to the European Communities and withdrawal from the European Union.

For most of her "subjects", the Queen was the only monarch they had ever known as she featured on stamps, banknotes, coins, and immortalised in popular culture.

She has been a witness to some of the biggest royal scandals ranging from the divorce of Charles and Diana to her second son Prince Andrew's alleged links to convicted paedophile Jeffrey Epstein and  more recently Harry and Meghan quitting royal life.

World leaders react:

Prime Minister Narendra Modi expressed pain in her demise and said the Queen will be "remembered as a stalwart of our times."

Canadian Prime Minister Justin Trudeau said Canadians will always remember and cherish "Her Majesty’s wisdom, compassion, and warmth".

UN Secretary-General Antonio Guterres said Thursday that he was saddened by the death of British Queen Elizabeth II.

"I am deeply saddened at the passing of Her Majesty Queen Elizabeth II, the queen of the United Kingdom of Great Britain and Northern Ireland," said Guterres in a statement.

He extended his condolences to the queen's family, the government and people of Britain, and the wider Commonwealth of Nations.

"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," said the statement.

The queen was a good friend of the United Nations, and visited its New York Headquarters twice, more than 50 years apart. She was deeply committed to many charitable and environmental causes and spoke movingly to delegates at the UN climate change conference in Glasgow last November, said the statement.

"I would like to pay tribute to Queen Elizabeth II for her unwavering, life-long dedication to serving her people. The world will long remember her devotion and leadership," Guterres said.