Reason Prince William went all out with birthday wish for Kate Middleton

Prince William’s birthday gesture for Kate Middleton is unique in a lot of ways, says an expert.

The Prince of Wales, who posted a special photo of Kate Middleton on their Instagram handle this week, has snubbed a lot of Royal traditions.

Reported Brontë Coy tells The Sun’s Royal Exclusiveshow, Bronte shared: “I was really taken aback, but in a delightful way by that tweet, because, as you said, it's quite remarkable. 

He adds: “I'm going to use a word that's been used so many times in the last five years across the board, but it felt quite unprecedented, particularly for a non major birthday. “

The expert continues: “It's a 43rd, typically the royals are a little bit more low key with their personal messages, particularly William.”

Celebrating Kate, William said on the birthday message: "To the most incredible wife and mother.

"The strength you’ve shown over the last year has been remarkable. George, Charlotte, Louis and I are so proud of you.

"Happy Birthday, Catherine. We love you. W,” he concluded.