According to her death certificate that was published on Thursday, the Queen died of old age. Whereas for the Queen Mother, who passed away on 30 March 2002, the cause of death was officially noted down as "extreme" old age.
WATCH: The Queen's Funeral - The most emotional moments
The Queen Mother had been suffering from a cold in the days leading up to her death, unlike her daughter who, despite the fact she had been coping with ongoing mobility issues, had no reports of any contributing illnesses leading up to her passing.
On her official death certificate, the Queen's exact time of death was recorded and revealed to be a ten past three in the afternoon which contrasted with her mother and her late husband Prince Philip, for whom their exact time of death was never confirmed.
It was recorded, however, that the Queen Mother passed away at her official royal residence, Royal Lodge, Windsor.
On the day of her death, Buckingham Palace released a statement which read: "The Queen, with the greatest sadness, has asked for the following announcement to be made immediately: her beloved mother, Queen Elizabeth, died peacefully in her sleep this afternoon at Royal Lodge, Windsor. Members of the royal family have been informed."
The Queen Mother passed away in March 2002
Both the Queen and her mother enjoyed long lives with Queen Elizabeth II, passing away aged 96, and her mother aged 101.
On the eve of her mother's funeral, one week after her mother's death, the Queen, dressed respectfully in a black outfit and delivered a televised address from Windsor Castle, during which she thanked the public for their support.
She said: "Ever since my beloved mother died over a week ago I have been deeply moved by the outpouring of affection which has accompanied her death.
The Queen and her mother pictured with Princess Margaret and King George VI at Royal Lodge
"My family and I always knew what she meant for the people of this country and the special place she occupied in the hearts of so many here, in the Commonwealth and in other parts of the world.
"But the extent of the tribute that huge numbers of you have paid my mother in the last few days has been overwhelming. I have drawn great comfort from so many individual acts of kindness and respect."
The Queen also paid tribute to the Queen Mother saying: "Over the years I have met many people who have had to cope with family loss, sometimes in the most tragic of circumstances.
"So I count myself fortunate that my mother was blessed with a long and happy life. She had an infectious zest for living, and this remained with her until the very end. I know too that her faith was always a great strength to her."
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