What will Japan's Emperor Naruhito get up to on his previously-delayed UK state visit?
The state visit by Emperor Naruhito and Empress Masako of Japan is finally underway after suffering a previous postponement, a possible cancellation following the King’s cancer diagnosis, and then a last-minute scaling back as a result of the UK’s snap General Election.
But it may not feel very scaled back when you see the carriages and horses process back to Buckingham Palace, and then on to the State Banquet tonight where both King Charles and his guest, the Emperor, will make speeches.
The Mall is lined with the recognisable flag of the rising sun and the formal welcome, as they always are, will take place in a ceremony at Horse Guards Parade.
The Japanese Emperor has already been in the UK for several days, undertaking private visits with his wife, having arrived at Stansted Airport on Saturday.
That included a visit to the world-famous Thames barrier as Emperor Naruhito is a big fan of the River Thames and has studied it closely when he was younger.
Both the Emperor and Empress studied at Oxford University, so a visit to their former college is also part of their programme of events. It will take place on Friday.
Today, however, marks the official start as Prince William meets the couple at their hotel and escorts them to the ceremonial and military welcome parade with King Charles and Queen Camilla.
Following a royal salute from the Guard of Honour, formed of the 1st Battalion Welsh Guards, the Japanese national anthem will be played by the Band of the Welsh Guards.
The two royal couples will then head back to the palace in a carriage procession for the tried and tested state-visit ritual of lunch followed by an inspection of items from the Royal Collection, which relate to Japan.
The Emperor and Empress also have a visit at Westminster Abbey to squeeze in, where the Japanese head of state will lay a wreath at the Grave of the Unknown Warrior.
The events of the day mean the election campaign will be put on pause by some of the political party leaders who have been invited to tonight’s State Banquet.
The Emperor has also requested a visit to the tomb of Queen Elizabeth II.
The late Queen was laid to rest at St George’s Chapel in Windsor following her death in September 2022 and Emperor Naruhito wishes to lay his own wreath there.
State visits are more than just about ceremony.
Both incoming visits, like this one, and foreign state visits when the King and Queen travel abroad are carried out on the advice of the Foreign Office with government priorities in mind.
Diplomats were keen to keep as much of this visit intact, despite the election, in order to avoid offending their Japanese guests.
Whilst the visit is a little pared back as a result, the Foreign Office is hopeful it will still enable the usual round of trade announcements to be made and business ties between the two countries to be strengthened.
This is the Talking Royals - our weekly podcast about the royal family, with ITV News Royal Editor Chris Ship and Producer Lizzie Robinson