Here are ten facts on how they managed it.
1. Prince George was baptised with the 17in-high silver gilt Lily Font, made for Queen Victoria's children, which is usually kept under guard with the Crown Jewels.
2. Water from the Jordan, where Christ was baptised by John the Baptist, was used. The archbishop made the sign of the cross and trickled water on his head three times to symbolise the Holy Trinity.
3. Baby George wore a replica of the royal family's 172-year-old robe.
4. The Duke and Duchess chose the hymns Breathe on Me, Breath of God and Be Thou My Vision. The latter was sung at the memorial service for the 10th anniversary of the death of Diana, Princess of Wales.
5. The venue – the Chapel Royal in St James's Palace – also paid a subtle tribute to William's late mother. It was here that her coffin lay at rest on the eve of her funeral in 1997. Previous members of the family have been baptised at Buckingham Palace.
6. Proud mum Kate wore Alexander McQueen, the same label that created her wedding gown.
7. The official photos brought together four generations of the royal family in the same image – the first time this has happened since 1894 when 80-year-old Queen Victoria posed with three of her heirs.
8. The Cabinet's christening gift to Prince George was a hand-crafted pine toy box made by Hibba Toys UK of Leeds. Ministers also made a charitable donation to the Royal Foundation of the Duke and Duchess of Cambridge and Prince Harry.
9. The Queen wore a brooch to the christening given to her by her parents, George VI and the Queen Mother, which marked the birth of Prince Charles in 1948. The brooch, made of rubies, diamonds and sapphires, is in the shape of a basket of flowers.
10. As godparents Willliam and Kate chose one relative, his cousin Zara Phillips, three personal friends of theirs from childhood or university, a trusted aide, and two family friends with connections to Princess Diana.
This is a complete break with tradition as in the past a future King would have had other royals, often from foreign countries, and aristocrats as mentors.