Although Queen Elizabeth and Prince Philip were not in attendance, Prince Charles and Camilla were joined by Kate's parents Carole and Michael Middleton and the the rest of the Middleton clan, including their brother James, Pippa and her husband James.
Prince Louis, the third child of Prince William and wife Catherine, the Duchess of Cambridge, been christened at a small, private ceremony overseen by close family but without his great-grandmother the Queen.
In April, she delighted fans when she accompanied her father and brother to the Lindo Wing to meet Prince Louis for the first time and began waving as soon as she stepped out of the family auto.
The Duchess of York, Sarah Ferguson, and Prince Andrew, christened their eldest daughter in December 1988. The little prince wore the same gown his older siblings wore to their christenings and continued the tradition.
Guests included the Duke and Duchess of Sussex and the Middleton family and the tea was held at Clarence House.
Behind them, Prince Charles and the Duke of Edinburgh. James, Viscount Severn, was the first baby to wear the new outfit at his christening in 2008.
Also on the guest list were the six godparents, announced by Kensington Palace on Monday morning.
At the christening of William's children, there has usually been a poignant nod to the duke's late mother Diana, Princess of Wales, who was killed in a vehicle crash in 1997.
The cozy (seats less than 50) chapel's long history (it was built starting in 1540) is steeped in royal connections and ceremonies.
Guy Pelly: The son of wealthy Kent landowners, Mr Pelly used to help run several London nightclubs. Prince William formerly served as an RAF search-and-rescue pilot, while Prince Harry received helicopter training from the RAF during his time in the Army Air Corps.
Her outburst didn't last long, though, after she was picked up and comforted by her mother, adds Time magazine.
Harry Aubrey-Fletcher: He went to Ludgrove School and Eton with William and his father is the Lord Lieutenant of Buckinghamshire.
Lucy Middleton: She is the Duchess of Cambridge's cousin and a solicitor.