The Emperor and Empress of Japan received a ceremonial welcome of military pomp and pageantry as their state visit began.

The King and Queen greeted their guests on Horse Guards Parade where some of the nation’s most prestigious regiments were on display.

The two heads of state warmly shook hands as did their wives under a large purpose-built pavilion that shielded them from the blistering summer sun.

The Prince of Wales had escorted the emperor and empress from their overnight residence, arriving almost 10 minutes late in chauffeur driven cars.

Missing from the state visit is the Princess Royal, who spent a second night in hospital after suffering minor head injuries and concussion after she was reportedly kicked by a horse on her Gatcombe Park estate on Sunday.

The three-day state visit comes in the midst of a General Election. During Queen Elizabeth II’s 70-year reign there were no incoming state visits at the same time as a general election.

The Prince of Wales shakes hands with the Empress of Japan
William escorted the visitors to Horse Guards Parade (Jordan Pettitt/PA)

A Japanese foreign ministry official said the emperor and empress’s visit would not be a political one and it was hoped it would forge “friendly relations across generations” between Japan’s imperial family and the British royal family.

In 2017, a Spanish state visit by King Felipe VI was quickly rescheduled – after an agreement between the late Queen and King Felipe – because the date clashed with a snap election in the UK.

A Palace spokesman said this week’s programme had been “slightly adapted”, adding: “As a general principle, it has of course been adapted as a result of the current pre-election period of sensitivity.”

Missing elements appear to be the usual Downing Street talks with the Prime Minister, a speech to the Palace of Westminster by the visiting head of state, and meetings with opposition leaders.

Waiting on the parade ground was a guard of honour formed by the 1st Battalion Welsh Guards who, when not performing ceremonial duties, are fighting soldiers.

They were joined on parade by the Mounted Band of the Household Cavalry with their magnificent Shire Drum Horses, leading four divisions of the dazzling Sovereign’s Escort of the Household Cavalry Mounted Regiment.

In the distance could be heard the low rumble of a 41-gun royal salute fired from Green Park by the King’s Troop Royal Horse Artillery and at the Tower of London the same number of volleys was fired by the Honourable Artillery Company.

The Japanese national anthem was played, and the Emperor inspected the guard of honour, accompanied by the King, who walked a few paces behind his guest.

The King and Emperor Naruhito of Japan travelling together in a coach
The King and Emperor Naruhito of Japan travel together in the lead coach (Jonathan Brady/PA)

The King wore a morning suit with a top hat, and he briefly removed his headwear as a mark of respect when he passed the regimental colours.

Watching from the pavilion were the royal women, the Queen, wearing an Anna Valentine dress and Philip Treacy hat, and the empress along with the waiting dignitaries, including foreign secretary Lord Cameron, Home Secretary James Cleverly and Metropolitan Police Commissioner Sir Mark Rowley.

At the end of the welcome ceremony was the traditional carriage procession to Buckingham Palace where a private lunch will be held.

The two heads of state sat together in the lead coach, followed by Camilla and the empress who has an allergy to horse hair and as a precaution wore a face mask.