Her eldest son Charles, 73, automatically becomes king of the United Kingdom and the head of state of 14 other realms including Australia, Canada and New Zealand.
The royal family had rushed to Scotland’s Balmoral on Thursday after doctors said the monarch was not feeling well and should stay “under medical supervision”.
In spite of Buckingham Palace’s prior statement, announcing that “the Queen remains comfortable and at Balmoral,” she passed away.
According to the Buckingham Palace, Queen Elizabeth II was suffering from “episodic mobility problems” since the end of last year.
The development came after the queen appointed Liz Truss as the new British prime minister on the previous day.
Elizabeth was the queen of Britain and more than a dozen other countries, who saw 15 British prime ministers in her record-breaking reign and earlier this year marked her 70th year on the throne, Press TV reported.
Her last years as the monarch were marked by a slew of scandals dogging the royal family.
The Sunday Times recently reported that Prince Charles, the heir to the British throne, accepted a £1 million ($1.19 million, 1.21 million euro) donation from the family of the deceased Saudi terrorist, Osama bin Laden.
Neither Charles nor other members of the British royal family who had ties with Nazis or were entangled in numerous sexual affairs have been strangers to controversy and scandals.
From the 1970s to 90s, Charles and Camilla Parker Bowles were in a publicly-acknowledged illicit affair, which eventually resulted in Queen Elizabeth forcing the Prince and Princess Diana to get divorced in 1995.
Another one of the many scandals was when the Queen's second son, the Duke of York, was embroiled in a sex-slave relationship with an underage girl.
Buckingham Palace initially tried to defend the "honor" of Prince Andrew and quash the spreading news.
When the facts came out eventually, Andrew was stripped of all his titles by the queen.