Prince Harry gesture is latest move in new protocol after Meghan Markle and Prince Andrew messages

The Firm's chose a picture from a visit to a start-up in Dublin in 2018 when Prince Harry was still a working royal.

However, the picture did not include his wife, Meghan Markle who was with him at the event and was seemingly cropped out by the photographer at the time.

It has been stressed privately that, while the Royal Family don't mark non-working royal birthdays on their social media, the post was in line with the "tradition" of sending public good wishes on "significant" birthdays.

It is the same protocol being done to mark Meghan Markle and Prince Andrew's 40th and 60th birthday's, respectively.

Daily Mail diary editor, Richard Eden, wrote on social media: "This is intriguing: Buckingham Palace has previously said birthday wishes were sent on social media only to 'working royals'."

Harry, who lives in California after stepping down from the working monarchy, spent his birthday on Sunday with the Duchess of Sussex and their children Prince Archie and Princess Lilibet.

LATEST ROYAL NEWS

• William left 'flinching' at Kate and James Middleton's 'ruthlessness'
• Harry and Meghan attend tennis tournament as part of duke's birthday celebrations
• Meghan suffers fresh blow as 'everyone is terrified' of the Duchess of Sussex

When the King’s shock health news was announced in February, Harry made a transatlantic dash to see him but his meeting with his father was kept to just 45 minutes.

In comments released to the BBC, the duke said “I was anxious about 30, I’m excited about 40”, and described how fatherhood had given him a renewed sense of purpose to make “this world a better place”.

Harry’s year has seen him try his hand at the skeleton bobsled when he joined Invictus Games competitors training in Canada, and undertake quasi-royal tours to Colombia and Nigeria. In Colombia, Meghan addressed a panel on Afro-Descendant Women and Power and told how her three-year-old daughter Lili had “absolutely found her voice”.

The couple also relaunched their Archewell website, rebranding it as Sussex.com under the title The Office of Prince Harry and Meghan, the Duke and Duchess of Sussex.

The Duke told the BBC: "Becoming a father of two incredibly kind and funny kids has given me a fresh perspective on life, as well as sharpening my focus in all my work."

"Being a dad is one of life’s greatest joys and has only made me more driven and more committed to making this world a better place."