What is ‘Operation London Bridge’, the British protocol for the day Queen Elizabeth II dies

AS – The phrase ‘London Bridge is down’ will be used to inform family members, foreign diplomats and top officials that the monarch has passed away.

Buckingham Palace has confirmed that Queen Elizabeth II’s health has deteriorated in recent days, requiring her be placed under medical supervision after doctors were “concerned” about her health.

The 96-year-old has not been hospitalised and will remain at her Balmoral Castle estate where she spent her summer. Her son and heir Prince Charles has already arrived at the site, while his eldest son, Prince William, is thought to be travelling to Balmoral too.

“Following further evaluation this morning, the queen’s doctors are concerned for Her Majesty’s health and have recommended that she remain under medical supervision,” the statement read.

After 70 years on the throne the United Kingdom may soon experience a change of monarch for the first time in multiple generations. The eldest child, Prince Charles, is next in line for the throne and would technically become the monarch the very second the Queen passes away.

However there is a more convoluted process to get the message out and announce details of the succession.

What does ‘London Bridge is down’ mean?

Planning for the death of Elizabeth II has been in place for decades, with governments and broadcasters involved in getting the message out quickly and respectfully. An in-depth report from the Guardian describes this process, along with its codename: London Bridge is down.

The Queen’s senior doctor Sir Huw Thomas will oversee the final hours, during which she will likely be visited by close family and friends. He will control access to the room and decide what information is made public and which details should remain private.

The title of monarch is one which is passed down to the eldest heir and the transition technically occurs the second that the previous monarch dies. When it happens, Charles will become king and his siblings will kiss his hand to pledge their allegiance to him.

Beyond the immediate family, news of the Queen’s passing will begin with her private secretary, Sir Christopher Geidt. The former diplomat received a second knighthood in 2014, in part for his role in planning Elizabeth II’s succession, and it will be his duty to inform the Prime Minister, Liz Truss.

In 1952, when Elizabeth’s father George VI passed away, news of his death was conveyed using the code “Hyde Park Corner,” to maintain discretion. For Elizabeth II, the phrase “London Bridge is down” will be used to alert the PM and the heads of 15 other government where the Queen is head of state that she has died.

From there, the message will be sent to the 36 other Commonwealth nations where she continues to serve as a symbolic figurehead. From this point on the message will be shared by broadcasters and news agencies around the world and details of the funeral arrangements will be made public.

However so full of tradition and ceremony is the United Kingdom that there are other plans for different situations in the Queen’s final days. Another protocol, known as Operation Unicorn,  outlines what would happen if she dies in Scotland.

The Queen has spent the summer in Balmoral Castle, her Scottish residence, and her family has travelled to visit her there today. This means that there is a good likelihood that she will be in Scotland when she passes away and a separate process will be required to allow her body to lay in rest close to Balmoral, before being transported down south for burial in London.