Queen Elizabeth II is the longest reigning monarch the Britain has ever seen. At 92 years of age, the Queen has held the crown for 66 years after ascending to the throne in 1952 when her father King George VI died.
However, sadly her reign will come to an end when she eventually dies, and the royal family have a strict protocol in place when it does happen.
This is what we know so far:
Who will be the first to know when the Queen dies?
Queen Elizabeth's senior doctor gastroenterologist Professor Huw Thomas will be constantly monitoring her health in the lead up to her passing, and will be the person to confirm her death, The Guardian reports.
Then apart from her family, the first official to know of her death will be her private secretary, who is currently Edward Young.
London Bridge Is Down
The (not so) secret code that will be used to tell the UK Prime Minister that the Queen has died will be "London Bridge is down". The Queen's private secretary, Young, will relay those words over a secure line.
After that, the 15 governments outside the United Kingdom (including Australia) where Queen Elizabeth is the head of state, and the remaining Commonwealth nations where she has served as a figurehead will be informed.
When will the public know Queen Elizabeth has died?
When the Queen dies, an alert will first be sent to the Press Association and then other global media outlets shortly after. This is when the news will be reported and the world will know of her passing.
Following the alert, a footman dressed in mourning attire will place a notice on the gates of Buckingham Palace which details of a 10-day mourning period. The official palace website will also share the message and change the background colour to black.
If you happen to be on a flight when it happens, the plane pilot will inform passengers of the news.
What will the Queen's funeral be like?
Before the funeral, her body will lie in state in Westminster Hall so members of the public can pay respect to their queen. On the day of her funeral, which will be a public holiday, her body will be transported to Westminster Abbey by gun carriage for a state funeral.
A-list celebrities, world leaders and of course members of the royal family will all be in attendance. It is not yet confirmed where she will be buried, but it could be St. George's Chapel or Frogmore Gardens.
When will Charles become King?
Shortly after his mother's passing it is said that Charles will address the public as the head of state and the following day he will be named as King.
However, his coronation will not occur until at least a year after the Queen's death.