Elizabeth II was 96-years-old and her death comes after 70 years on the throne.
The death of the Queen will result in a range of changes across Britain, with a new monarch King Charles III taking the throne, the changing of the national anthem and also a major change to our currency.
Here is what you need to know:
How will British coins and notes change after the Queen’s death?
Elizabeth II is the face of the currency in Britain.
Her face is on coins and notes.
Following the accession to the throne by Charles - who will be the third monarch of his name - there will be a major change to our currency.
The face of King Charles III will be printed and minted on future coins and notes.
What will happen to notes with the Queen’s face on?
The old notes and coins featuring the profile of will slowly be removed from circulation - the way that older forms of bank notes were in recent years.
New notes and coins featuring King Charles will be introduced in their place.
Notes with Queen’s face will remain legal tender
Current bank notes featuring a portrait of the Queen will continue to be legal tender, the Bank of England has reassured consumers.
A further announcement regarding notes will be made once the period of mourning has been observed following the Queen’s death.
The Queen was the first monarch to feature on Bank of England banknotes, Threadneedle Street said.
Bank governor Andrew Bailey said: “It was with profound sadness that I learned of the death of Her Majesty The Queen.
“On behalf of everyone at the Bank I would like to pass on my deepest condolences to the Royal Family.
“For most of us, she is the only head of state we have ever known, and will be remembered as an inspirational figure for our country and the Commonwealth.”
Will the change affect other countries?
Britain is not the only country where currency changes will have to be made.
The face of Elizabeth II is featured on notes and coins in Commonwealth countries such as New Zealand, Australia and Canada.
In these countries, old notes featuring the profile of the Queen will also have to be eased out of circulation and replaced by ones featuring King Charles.
What plans are in place when the Queen dies?
Although plans have been in place for decades in a process dubbed “Operation London Bridge”, a series of documents obtained by political news outlet Politico details the specifics of the protocols when the monarch dies.
The security plan is outlined in full, detailing everything from how news of the monarch’s death will be shared to the public to how quickly Prince Charles will ascend the throne.
It also includes details on what will happen during the 10 days following the Queen’s death, including where her coffin will go, how Prince Charles will spend his first few days as King and how the prime minister will publicly address the news.
The day that the Queen dies will be referred to as D-Day, with every day afterwards referred to as D-Day+1 and D-Day+2 and so on, going up to and including D-Day+10.
Her funeral will take place 10 days after the death of the Queen and it will take place at Westminster Abbey.