Prince George has been christened in a ceremony that spanned four generations of the royal family.
Making only his second public appearance the royal baby appeared in the arms of the Duke and Duchess of Cambridge - and took everything in his stride.
George blew bubbles as he was gently bounced by his father before the christening began at the historic Chapel Royal at St James's Palace.
And proud father William told the Queen, Duke of Edinburgh, Prince of Wales, Duchess of Cornwall and Prince Harry that the content infant was the "quietest" he had been all day.
When the 35-minute baptism service was over, the pink-cheeked, chubby and peaceful baby prince emerged, cradled by his mother, who beamed with delight.
The day was clearly a happy event for the royals and Kate's family - parents Carole and Michael Middleton and siblings Pippa and James - with a Kensington Palace spokesman saying after the service: "It has been a tremendously joyful occasion for everyone involved."
The three-month-old baby, who will one day be king, was last seen when he was a day old, following his birth on July 22.
On that occasion, William and Kate proudly showed him off to the world's media as they left the Lindo Wing of St Mary's Hospital in central London, and could not contain their joy as he slept peacefully.
Since then his father has revealed that George has a good pair of lungs but he appeared to be on his best behaviour today for his first official engagement.
Earlier the Cambridges announced George's seven godparents who include William's cousin Zara Tindall and the Duke and Duchess's former private secretary Jamie Lowther-Pinkerton, who continues to serve part-time as their principal private secretary and equerry.
Also chosen was Oliver Baker, who attended St Andrews University with William and Kate, and family friend Hugh Grosvenor, the son of the Duke of Westminster.
Another moral guardian for the baby prince is Julia Samuel, who was a close friend of Diana, Princess of Wales, and is the founder patron of Child Bereavement UK, which has William as its royal patron.
William van Cutsem is one of four brothers who are old family friends of William and Harry, while Emilia Jardine-Paterson is an interior designer who went to Marlborough College with Kate.
The Archbishop of Canterbury, the Most Rev Justin Welby, who conducted the christening told George's parents and godparents that they had a "simple task" to "make sure he knows who this Jesus is".
He added: "Speak of him, read stories about him. Introduce him in prayer. Help him to grow and flourish into the person God has created and has called him to be."
Harry and Pippa gave bible readings and the service also featured two hymns, two lessons and two anthems chosen by William and Kate, who wore a cream Alexander McQueen outfit and a matching hat by Jane Taylor.
One extra guest was the duke's former nanny Jessie Webb who left the chapel chatting to George's grandfather Michael Middleton.
Ms Webb has been helping the Cambridges with child care duties on an ad hoc basis and attended the christening in her role as nanny.
The day ended with the guests enjoying afternoon tea at Clarence House hosted by Charles and Camilla, with the royals, Middletons and godparents served slices of christening cake - taken from a tier of the Cambridges' wedding cake.