Princess Charlotte's favourite joke hilariously recounted by Prince William

Footage has re-emerged of Prince William delivering Princess Charlotte's favourite joke - and the gag was adored on social media.

Prince of Wales, 42, told children at St Michael's School in Rowley Regis, West Midlands, the joke earlier this year when they asked him for a gimmick for an audio recording.

He says: "I am with the gang here talking about male mental health and I've been asked to produce a dad joke... I'm trying to channel Jack Whitehall, because most of his jokes are pretty dad-like."

After a moment of hesitation, William continues: "What I'll do is I'm going to say a joke that's Charlotte's favourite joke at the moment, she keeps telling me, I'll do that instead. You're going to have to interact with me, it's not a joke I can tell straight away."

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And then, he hits the room of pupils with it - "Knock knock," the royal says. The boys reply: "Who's there?" And father-of-three William says: "Interrupting cow." Before the boys had a chance to reply "Interrupting cow who?", William loudly went "Moo!"

Laughter - and groans - are heard from the children in the room at St Michael's School, a secondary school that serves more than 1,200 youngsters in the Black Country. To the groans, William says: "Yep, that's what I get a lot at home at the moment... That's the greatest one I can think of, it's clean and broadcastable."

William went to the school after a student named Freddie Hadley wrote him a letter last year, inviting him to learn about their mental health initiatives. The duo were photographed outside the school as William told the young boy: "I'm here now."

Footage of their encounter has been shared widely online, and continues to do so several months on. The joke is largely praised by social media users, with one stating: "It's absolutely hilarious." Another reads: "I hate to say it, but that's actually quite good."

But one social media user wrote: "Am I the only one who did not understand Charlotte’s joke?" Another tough critic described the gag as "embarrassing".