The late royal was the longest-reigning monarch in British history.
After 70 years on the throne, Queen Elizabeth II died on Thursday at age 96. Her death signifies a massive shift not just for the royal family, but for the world, who have known Elizabeth as the monarch of Great Britain and its sovereign countries since Feb. 6, 1952.
The royal family announced the queen's death with an official statement on their social media pages, sharing a portrait of the late monarch.
"The Queen died peacefully at Balmoral this afternoon," the statement read, before referring to the newly ascended King Charles III, her eldest son, who has succeeded his mother on the throne. "The King and The Queen Consort will remain at Balmoral this evening and will return to London tomorrow."
The new king also released a statement, saying, "The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family."
"We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother. I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world," the statement continued. "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."
Here's a look at the days leading up to the queen's death, and what will happen as her family and kingdom mourn the loss of Britain's longest-reigning monarch.
New speculation about the queen's health began in earnest when members of the royal family traveled to Balmoral Castle in Scotland on Thursday to be by the royal matriarch's side as doctors expressed concern for the 96-year-old British monarch's health.
Prince Harry, Prince William, and their father, Prince Charles, all made the trip to be by the queen's side, while Meghan Markle remained in London -- though royal reporters noted that she would not attend the previously planned WellChild Awards, part of the Duke and Duchess of Sussex's trip abroad.
"It's understood that the family wanted Prince Harry to be there, even though he was unable to get to Balmoral in time to see his grandmother, but Meghan, the Duchess of Sussex, was not, we understand, invited to join the family," royal expert Katie Nicholl told ET. "She has said she will go to Balmoral another time, but I think it is quite significant that Prince Harry traveled to Balmoral on his own without his wife."
Kate Middleton also stayed home to be with her and William's three children -- Prince George, 9, Princess Charlotte, 7, and Prince Louis, 4 -- as Thursday marked their first day of school at Lambrook School.
Elizabeth's other children, including Princess Anne, Prince Andrew, and Prince Edward, also made the trip to Scotland, as did Camilla, the Duchess of Cornwall, and Sophie, the Countess of Wessex.
The family visits came after Buckingham Palace released a statement on Thursday, saying, "Following further evaluation this morning, The Queen’s doctors are concerned for Her Majesty’s health and have recommended she remain under medical supervision. The Queen remains comfortable and at Balmoral."
Newly appointed Prime Minister Liz Truss, who met with the queen earlier in the week at Balmoral to accept her appointment, also 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."
The Official Announcement
The royal family announced the queen's death on Thursday with an official statement on their social media pages, sharing a portrait of the late monarch.
"The Queen died peacefully at Balmoral this afternoon," the statement read. "The King and The Queen Consort will remain at Balmoral this evening and will return to London tomorrow."
The World Reacts
Immediately after Queen Elizabeth's death was confirmed, tributes from all over the world poured in for the late monarch.
"The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family," Queen Elizabeth's son, who's now known as King Charles III, said. "We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother. I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world."
"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," he added.
Former U.S. President Barack Obama and his wife, Michelle Obama, released a statement following the monarch's death, saying in part, "Time and again, we were struck by her warmth, the way she put people at ease, and how she brought her considerable humor and charm to moments of great pomp and circumstance. Like so many, 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."
Meanwhile, Helen Mirren, who won both a Tony Award and an Oscar for her portrayals of Queen Elizabeth -- the former for The Audience and the latter for The Queen -- reacted to the late royal's death on Instagram.
"I am proud to be an Elizabethan," Mirren wrote alongside a photo of Queen Elizabeth. "We mourn a woman, who, with or without the crown, was the epitome of nobility."
For more insight, you can take in all the notable reactions to Queen Elizabeth's death.
What Comes Next
A series of royal protocols for the queen's death have long been in place. Had she died in London, the plan known as "Operation London Bridge" would have taken effect; her death in Scotland enacted a plan known as "Operation Unicorn" (so named for the country's official animal).
The queen's body is expected to be moved from Balmoral to Holyroodhouse Palace in Edinburgh, where members of the public can pay their respects. It will then be carried up the Royal Mile to St. Giles for a funeral service before being transported by the Royal Train back to London for the burial service.
In the hours following the queen’s death, Prime Minister Liz Truss, the cabinet secretary (Britain’s highest-ranking civil servant) and a number of the most senior ministers and officials were informed of the death, with the PM being informed by the queen’s private secretary. The prime minister was then the first member of the government to make an official statement, addressing cameras outside Downing Street.
"The death of her majesty the Queen is a huge shock to the nation and to the world," Truss said. "Queen Elizabeth II was the rock on which modern Britain was built. Our country has grown and flourished under her reign."
Following the royal household's official announcement, both through the news and social media -- with the royal family's website and social platforms displaying a black page with a short statement on the queen's death -- the U.K. parliament and the devolved legislatures in Scotland, Wales and Northern Ireland will be adjourned and a national moment of silence will be held.
Upcoming announcements will include the royal family's plans for the queen’s funeral, which is expected to be held 10 days following her death. She is expected to be buried in Windsor with her late husband, Prince Philip.
King Charles Crowned
Plans for Charles' ascension to the throne have also long been in the works, under the code name "Operation Spring Tide." The process began immediately following the queen’s death, when Charles was proclaimed the new monarch, King Charles III. Following an audience with the prime minister, the king is expected to address the nation and the world -- likely on Friday, following his return to London.
Members of British Parliament will then swear allegiance to the new monarch, followed by proclamations by the Scottish, Welsh and Northern Irish administrations.
The new monarch will then receive the motion of condolence at Westminster Hall and then depart for a tour of the United Kingdom, attending services in Edinburgh, Belfast and Cardiff before returning to London for his mother’s funeral. Plans for an official coronation ceremony will follow.
Charles' wife, Camilla, the former Duchess of Cornwall, is also now the new Queen Consort. The decision to give Camilla this title was at the "sincerest wish" of Queen Elizabeth herself, as announced in February 2022, when she celebrated her Platinum Jubilee.
"When, in the fullness of time, my son, Charles, becomes King, I know you will give him and his wife, Camilla, the same support that you have given me; and it is my sincere wish that, when that time comes, Camilla will be known as Queen Consort as she continues her own loyal service," said the queen in her message at the time.
For updates on Queen Elizabeth's death, visit ET's ongoing coverage and see more below.