The Duchess of Cambridge was in the early stages of labour when Henry was born, two days before his due date, at St John of God Murdoch Hospital.
Both Henry and the heir, Prince George of Cambridge, weighed in at 3.8kg.
Parents Eleanor and Carl, from Melville, were ecstatic to welcome a third son into the family, a baby brother for James (6) and Oliver (4) and are excited that he shares his birthday with a future king.
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READ NOWFather Carl, who is English, said he would contact the Royal Mint to see if Henry was entitled to one of the special silver pennies given to all English babies born on the same day as Prince George.