Donald Trump just broke major ‘royal protocol’ and King Charles might not be happy about it

Donald Trump and wife Melania may have just broken 'royal protocol', just minutes into the first full day of their UK state visit today (17 September).

According to The Mirror, the US president and First Lady were late to arrive and kept Prince William and Kate Middleton waiting.

They had reportedly had been due to meet the Prince and Princess of Wales at 12pm but Trump's Marine One helicopter only began hovering over the walled garden area of the Windsor estate at about 12:10pm.

Shortly after touching down, Trump and Melania were greeted by Kate and William and taken a short distance, where they met with King Charles III and Queen Camilla at the front of the gable-ended Victoria House.

The Buckingham Palace official website outlines that, while there are no obligatory codes of behaviour when meeting the King or members of the Royal Family, many people wish to observe the traditional forms.

Donald and Melania Trump may have already broken 'royal protocol' (WPA Pool/Getty Images)

This includes bowing or curtsying, as well as using correct formal addresses like 'Your Majesty' when speaking to the King.

And King Charles has previously made it clear that he's not a fan of having to wait.

During his coronation back in May 2023, he and Camilla arrived roughly five minutes early and had to wait inside the carriage before they could enter the church.

According to Sky News, an expert lipreader alleged that at the time, that while he was waiting, the King said: "We can never be on time."

He then reportedly added: "There's always something... this is boring." Ouch.

Today, the King had arrived with the Queen in the state Bentley at 12.02pm before heading inside Victoria House, where Charles could be seen standing just inside a door and watching the helicopter land.

Trump stepped out of the helicopter at 12.16pm, behind the planned time.

Once Trump and Melania met carriage procession route through the private Windsor estate to the castle were 22 half-companies of personnel from throughout the Royal Navy, the Royal Marines, the British Army and the Royal Air Force.

The group embarked on a carriage procession route through the private Windsor estate (WPA Pool)

Queen Camilla's attendance for today's events was initially called into question after palace representatives confirmed yesterday that the 78-year-old had been struck down with acute sinusitis. Thankfully, however, it was later confirmed that she would be there to welcome Trump.

After greeting each other, the Trumps joined the King and Queen and the prince and princess for the scenic carriage ride through the green parkland to the castle.

Some 120 horses and 1,300 members of the British military were involved in the ceremonial welcome at Windsor, with 160 personnel from the Royal Marines and Royal Navy, 1,000 from the British Army and 140 from the Royal Air Force.

The King and Trump could be seen engaged in conversation as the carriage procession set off, while Camilla and Melania could also be seen deep in discussion in the following carriage.

The Prince and Princess of Wales followed in the coach behind, and as the carriages proceeded along the route, the American and British national anthems were played.

Trump previously visited the UK for a state visit in 2019, where he was hosted by the late Queen Elizabeth II.

During the course of their stay this week, the Trumps will be invited by the British monarch to inspect the guard of honour. Charles and Camilla will then hold a state lunch, before taking the president to view a number of US-related items from the Royal Collection.

Sky News reports that a royal salute is also planned to be fired in Trump's honour around midday, from six First World War-era guns which are currently located on the east lawn of Windsor Castle, as well as the Tower of London.

And later in the day, Trump will lay a wreath upon the tomb of the late Queen.