Operation Unicorn - The codename for the Queen's death in Scotland

The codenames of events which unfold after the death of Queen Elizabeth II have long been in place and have been triggered after she died today.

Operation Unicorn is the codename used first and foremost as her death occurred at her Balmoral residence in Scotland. It runs alongside Operation London Bridge which spans the 10 days leading up to her funeral.

Below are the codenames explained:

This is the codename for the death of the Queen at Balmoral Castle, her summer residence in Scotland. Buckingham Palace announced the news of her death.

According to Scottish news outlet, Edinburgh News, following her death, the Monarch will be moved from Balmoral in Aberdeenshire to Edinburgh, where she is to rest in state at the Palace of Holyroodhouse.

The Queen's body will then be transported to London, where her state funeral will take place. It is understood she is to be buried with her husband, The Duke of Edinburgh, and parents at St George’s Chapel in Windsor.

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The Queen will lie in state at the Palace of Westminster for three days, in an operation codenamed Feather. This codename refers to the logistics outside Westminster Hall including arrangements for the public.

The coffin will lie on a catafalque open to the public. VIPs will be given a time slot to visit. A rehearsal for the state funeral procession will take place.

Thousands of people will queue in the streets as they wait to see the monarch’s coffin on its catafalque.

The codename Operation London Bridge is understood to run alongside Operation Unicorn. The former, refers to the plan following the death of the Queen and covers the schedule for the 10 days between her death and her funeral.

The hours after her death are known as D-Day. Meticulous planning has been in place for years with today's news triggering the day the official operations unfold.

Nine News outlines the 10-day plan:

Buckingham Palace notifies the public of the Queen's death. Prince Charles immediately succeeds to the throne upon his mother's death. He will be known as King Charles III. His wife, Camilla, becomes Queen Consort. The couple stay at Balmoral overnight.

Flags fly at half-staff across British government buildings. Charles issues a brief statement, as does UK Prime Minister Liz Truss.

Numerous commemorations are planned from moments of silence to military gun salutes and remembrances in honour of Elizabeth.

Charles returns to London. The Accession Council — a gathering traditionally held at St. James's Palace — meets, usually within 24 hours of a monarch's death. It formally declares Elizabeth's death and the new king's accession to the throne.

Parliament frames a message of condolence and suspends its normal business until after Queen Elizabeth's funeral.

King Charles III begins his duties.

The King will meet with the Secretary-General of the Commonwealth and the Dean of Windsor.

The coffin will be moved via hearse and road to Edinburgh to the Palace of Holyroodhouse where Elizabeth will be placed in the Throne Room for staff to pay their respects.

King Charles begins his tour of the UK and starts official duties.

This is an opportunity for him to meet with as many members of the public as possible across the country.

He will first visit Edinburgh in Scotland and will go to the Palace of Holyrood House for a guard of honour inspection.

There will be a ceremonial procession to St Giles Cathedral along the Royal Mile.

There will be a short service and Elizabeth will lie at rest for 24 hours at St Giles Cathedral.

King Charles will make his way to Belfast, in Northern Ireland to visit Hillsborough Castle, and then attend a remembrance service at St Anne's Cathedral.

Following this, he will return to London.

In the afternoon, the Queen's coffin will move from St Giles Cathedral to Waverley Station where she will travel on the Royal train to St Pancras, London. The expectation is that people will line the train line the length of the country as the Queen makes her final journey through the United Kingdom.

The Queen arrives at St Pancras, London in the morning. She will then be taken by hearse to the Bow Room at Buckingham Palace.

The day begins with the Imperial State Crown, orb and sceptre and flowers being placed on the Queen's coffin. The royal family will hold prayers.

At 1.30am NZT, (2.30pm local time) a gun carriage procession will take the coffin from Buckingham Palace to Westminster Hall at the Palace of Westminster.

Here, it is expected members of the family and palace staff will walk on foot behind the procession, which will travel past the Queen Victoria Memorial and on to Pall Mall, through the Horse Guards Parade, Whitehall, Parliament Square and into New Palace Yard.

At 2.00am NZT (3pm local time), the coffin will arrive at Westminster Hall and be moved inside.

A short service will be held by the Archbishop of Canterbury with the royal family in attendance, before they return to Buckingham Palace.

From here, the lying in state begins. It will continue for five days, with hundreds of thousands of people expected to visit the Queen at Westminster Hall.

A day of mourning.

No public events are to take place on this day and the King will not be seen in public.

King Charles resumes his tour and will go to Cardiff and Wales to attend a remembrance service at Llandaff Cathedral, visit the Senedd and then have an audience with the First Minister at Cardiff Castle.

Members of the public will be invited to attend a reception at the castle.

From here, the King will return to London in the afternoon, meeting faith leaders at Buckingham Palace.

A vigil will be held at Westminster Hall in the evening, attended by members of the royal family.

World leaders, dignitaries and officials are expected to begin arriving from around the world.

The King will meet with governors generals and prime ministers from the Commonwealth realms at Buckingham Palace.

Funeral arrangements are finalised and a reception for foreign royals will be held at Buckingham Palace, followed by an evening reception for foreign leaders and dignitaries.

The United Kingdom and the world farewells Queen Elizabeth II.

The lying in state ends at 7.30pm NZT (8.30am local time). Two hours later, the Queen's coffin will be moved from Westminster Hall to Westminster Abbey.

The funeral will begin at around 9.50pm NZT (10.50am (local time) and finish at 11pm NZT.

A gun carriage procession will take the coffin back past Buckingham Palace, arriving at Hyde Park Corner at 12am NZT (1.00pm local time).

The coffin will then be moved on to a hearse and begin its journey by road to Windsor Castle, where a committal service will be held at St George's Chapel at 3.00am NZT (4.00pm local time).

At the end of this service, the coffin will be lowered into the Royal Vault. A private burial will be held with the King and other members of the royal family that evening and the Queen will be laid to rest.

A time of national mourning begins and flags across the country will be returned to full-mast.

The time of mourning will be determined by the British Government.

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Operation Spring Tide is the plan for the Prince of Wales' ascension to the throne, starting the day after the Queen’s death when he will be proclaimed the new king by the Accession Council at St James's Palace.

Operation Spring Tide works alongside Operation London Bridge. King Charles is scheduled to make his first address as the new head of state on the evening of his mother’s death.

King Charles' official coronation is likely to take place up to a year after the Queen's funeral. This will be a public holiday in the UK.

Currency will be reprinted with the King's portrait and the Queen's currency will begin to be removed.

This will also happen for passports, stamps and official uniforms. The British national anthem will be changed to "God Save the King".

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