LONDON, United Kingdom (AFP) – Queen Elizabeth II died of "old age" at 3:10 pm (1410 GMT) on September 8, according to her death certificate newly released on Thursday by the National Records of Scotland.
The 96-year-old monarch died at her Balmoral estate in Scotland around three-and-a-half hours before the news was announced to the world.
The queen was laid to rest on September 19 after a grand state funeral in London and a committal service at St George's.
Her coffin was transferred to the adjoining King George VI Memorial Chapel, alongside her father, King George VI, and her mother, also named Elizabeth.
The queen’s husband Prince Philip, who died last year, is also interred there, as are the ashes of her younger sister, Princess Margaret.
On Thursday, hundreds of people lined up outside Windsor Castle, as the landmark royal residence and its historic St George's Chapel, where the queen was buried last week, re-opened following her death.
Long queues of tourists, many with advance tickets, stretched back along the narrow streets outside the castle's stately walls for a chance to visit.
Royal palaces and residences have been closed since the death of the queen, including Windsor, west of London, where she spent much of her time.
"We grew up knowing the queen, respecting her. We felt very close to her," said Julie Davies, 67, from Upton in northwest England, who was visiting with her husband Allan, 62.
"It's very emotional, it means a lot," he added.
Elizabeth II was Britain's longest-serving monarch in history, spending 70 years on the throne.
She often prayed at St George's Chapel, which dates back more than 500 years.
The memorial chapel, which was completed in 1969, was commissioned by Elizabeth as a permanent resting place for her father.
The king died aged 56 in February 1952 but his death had been unexpected and as a result no specific resting place had been allocated.
Vivian Bjorkenstamn, 65, from Toronto, said she was there "specifically to pay respects and show my gratitude for the queen".
"She is part of our DNA... a wonderful woman to admire and to emulate," she added.
For her father, the queen rejected the idea of the traditional marble chest tomb with life-sized effigies favoured by earlier royals.
Instead his grave was marked with a simple black marker stone laid into the floor.
The stone now records the birth and death dates of Elizabeth, Philip and Elizabeth’s parents.
Amy Schrader, 34, and her sister Sarah Exner, 28, from Washington DC, said they had been determined to secure tickets.
"We were affected by the queen’s death. We came to celebrate her life, to see her grave and pay our respects," Schrader said.
To be among the first to see the grave was unexpected but "definitely something so special".
"It gives me goosebumps just thinking about that. We feel extremely honoured," she added.