King Charles’ Coronation and the inside story of Harry’s flying visit to …

In his heart, Prince Harry knew for the best part of a month that he was going to be at his father's Coronation.

A trusted former equerry, who is one of the very few still on good terms with both Harry and Prince William, was made aware of Harry's plans at the beginning of last month.

What Harry has been describing as an "in-and-out job", the fly-by visit will not allow him to catch up with that one-time inner core of UK-based friends, which now numbers only around six people.

Harry's delay in confirming his attendance has been widely put down to gripes over being placed behind senior royals for the Westminster Abbey service.

But a key issue has been his determination for the status of his children Archie and Lilibet to be publicly recognised by the royal family.

As the Coronation date, May 6, is the same day as Archie's fourth birthday, it offered the perfect opportunity for the King's fourth grandchild to receive some special recognition.

Charles was said to be open to the suggestion that he should make a gracious nod to Archie and rumours circulated that he would raise a glass to his grandson during a post-procession Coronation lunch.

Camera Icon Meghan won't attend the Coronation, because she will be at home hosting Archie's fourth birthday. Credit: Matt Dunham/AP

A source said: "The King considered a toast to Archie.

But with no member of the Sussex family now due at the lunch, it is highly unlikely he would do in their absence."

The whole episode has been described by courtiers as "a tug of war" -- one that has become typical of Buckingham Palace's engagement with the Sussexes.

There's nothing more "triggering" for Harry than wrangling over protocol, rules, hierarchy and perceived slights.

Other discussion topics have included Buckingham Palace balcony positions.

Camera Icon Balcony positions are a hotly contested topic in royal circles ahead of the Coronation. Credit: AP

As well as guidance that stops young children from being in Westminster Abbey, the King's aides have stuck firmly behind the protocol that only working members of the royal family should appear on the balcony in front of crowds.

Thus no space for Harry -- or Prince Andrew for that matter.

Friends of Harry, though, point out that after the late Queen's Coronation, she had both Charles and Anne on the balcony.

A further grievance is the relationship between Harry and his cousin Princess Eugenie, which is claimed to be strained, particularly after her mother, the Duchess of York, said Meghan "can't have it both ways" when it comes to being part of the royal family.

Eugenie may therefore be in an awkward position if she meets Harry on May 6.

As for quibbles over "placement", they are nothing new for the Sussexes.

There were misunderstandings over "who sits where" at a West London dinner party when Harry and Meghan were dating in 2016.

There was similar awkwardness at a London dinner hosted by Jack Mann, a polo-playing friend of Harry's, and then at Pippa Middleton's wedding reception, where Meghan was seated separately from Harry and their view of each other was obscured by a table decoration.

Camera Icon Kate, William, Harry and Meghan walk to meet mourners at Windsor Castle after Queen Elizabeth II died. Credit: Chris Jackson/AP

Most significantly, there were issues about seating during the Platinum Jubilee, for a Commonwealth Day service and for the late Queen's funeral, when the Sussexes were in a corner at the end of the second row -- with a candle obscuring cameras' clear view of the Duchess.

For Harry, this was the equivalent of social Siberia.

All this might explain why Harry has allocated just 36 hours to his trip -- which will be facilitated by a Cessna private jet which he's thought to use from Luton Airport.

A source says: "Harry plans to attend the Coronation and celebrate Archie's birthday on the same day.

"The flight back to Los Angeles takes roughly ten hours, which means he'll be with his family by 5pm, have a birthday supper with Archie and kiss him goodnight."