Happy birthday to the Duke of Sussex!

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Britain's Prince Harry, the younger brother of Prince William, Duke of Cambridge, turned 35 on Sunday, marking his first birthday as a dad.

Harry's wife, Meghan, Duchess of Sussex, celebrated the occasion with a heartfelt social media tribute to the new father, who welcomed son Archie Harrison Mountbatten-Windsor in May.

"Your service to the causes you care so deeply for inspires me every day," the duchess, formerly known as Meghan Markle, wrote in an Instagram post. "You are the best husband and most amazing dad to our son. We love you. Happiest birthday!"

A collage of nine photos, including a new snapshot from Archie's christening, accompanied the message, CNN reported.

Meghan wasn't the only royal to wish Harry a happy birthday. The official Twitter accounts for Clarence HouseBuckingham Palace and Kensington Palace also shared photo tributes to the prince.