Kate, 36, arrived carrying a snoozing 11-week-old Prince Louis and was greeted by the Archbishop of Canterbury at the Chapel Royal at St James’s Palace, London.
Pregnant Pippa Middleton was also at the service, along with the little boy’s godparents, Nicholas van Cutsem, Guy Pelly, Harry Aubrey-Fletcher, The Lady Laura Meade, Hannah Carter and Lucy Middleton.
Sadly the Queen and Prince Philip couldn’t attend the special day after a schedule clash.
Kate gave birth in April when she was admitted to the private Lindo wing of St Mary’s Hospital in Paddington, London.
Kensington Palace tweeted at the time:
“Her Royal Highness The Duchess of Cambridge was safely delivered of a son at 1101hrs.
The baby weighs 8lbs 7oz.
The Duke of Cambridge was present for the birth.
Her Royal Highness and her child are both doing well.”
They also said,
“The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news.”
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Kate and William announced their happy news in October 2017 with this adorable tweet.