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23 July 2013 Last updated at 06:00 BST
The baby was delivered at 16:24 BST at St Mary's Hospital in Paddington, west London, weighing 8lb 6oz.
The duke is based at RAF Valley on Anglesey, north Wales, where he and his wife share a cottage.
Flt Lt William Wales - who, as monarch, will one day be head of the armed forces - has spent recent years flying rescue missions, and qualified as a helicopter captain in 2012.
Here is what his colleagues had to say to him.
Wales welcomes 'joyous' royal birth
RAF crewmates of Prince William have sent their congratulations to him and the Duchess of Cambridge after the birth of their son.