Royal expert reveals meaning behind Prince William's 'curt' birthday message to Prince Harry

William and Kate's message on Prince Harry's birthday was a stark contrast to previous years. Photo / Getty Images

William and Kate's "curt" birthday wishes for Prince Harry on his 37th birthday prove the "ice hasn't thawed" between them, a royal expert claims.

According to The Sun, the Twitter message with the simple words "Happy Birthday Prince Harry!" shows the royal brothers have a way to go before the rift between them is mended.

Royal writer Duncan Larcombe told the outlet, "William and Kate's curt birthday message to Harry only serves as proof the ice between the brothers has still not thawed.

"Short of ignoring the Duke of Sussex's 37th landmark completely, their social media post was the bare minimum from a couple who once welcomed Harry as their official royal gooseberry.

"If anything, this year's birthday wishes from the Cambridges are an indication of just how far relations between the two warring clans have deteriorated over the past 12 months."

All three of the royal family's main social media accounts wished the Duke a happy birthday online, despite ongoing tensions between them.

Larcombe compared the Cambridges' message to Harry this year to their "happier" birthday wishes on his birthday last year.

"On the same day in 2020, William and Kate posted a longer message complete with birthday cake emoji and a red balloon, above a picture throwing back to happier times.

"The image they chose showed the Fab Three – as they were then – racing each other on the track during a joint visit to a mental health charity. It showed them all in mid-sprint sporting huge smiles on their faces.

"And a year earlier the contrast with today's post by William is even more telling."

He went on to add that it was "surprising" that William didn't share snaps of the brothers together as they remembered what would have been their mother Diana's 60th birthday earlier this summer.

Happy Birthday Prince Harry! 🎈 pic.twitter.com/Lw1nR9wNDl

— The Duke and Duchess of Cambridge (@KensingtonRoyal) September 15, 2021

"That would have sent a message of unity and the shared common bond between siblings who were once as thick as thieves," he commented.

None of the royal family's birthday messages to Harry over the past four years have featured his wife Meghan Markle.

Prince Harry hasn't seen much of his family since his royal exit last year, as Covid-19 continues to create huge obstacles for travel.

However, he has already been back to the UK twice this year - and could be returning once again soon so that the Queen can meet his second child, her namesake baby Lilibet.

It's likely the father of two marked his birthday at home with the help of Meghan and their children, though details of the celebration have been kept under wraps.