Much to the public's surprise, neither the Queen nor the Duke were present, though the palace insisted that this was the plan all along. It was also pointed out that both Her Majesty and Prince Philip are in fine health.
Also in attendance were Louis' godparents -- Nicholas van Cutsem (a family friend of William and Harry), Guy Pelly (one of the princes' best friends), Mr. Harry Aubrey-Fletcher, Mrs. Robert Carter and Miss Lucy Middleton, Catherine's cousin.
It's common for royals to choose six or seven people to serve as godparents to their children. The selection usually consists of close friends of the family and cousins (rarely siblings, except in the case of Prince Harry; one of his godparents is his uncle, Prince Andrew)
Fun fact: Guy Pelly is married to the Holiday Inn heiress, Lizzy Wilson.
Louis was dressed in a replica of the Honiton lace gown first worn by Queen's Victoria's oldest daughter in 1841. Children and grandchildren of Elizabeth II all wore the gown, with the exception of James, Viscount Severn.
The wear and tear of the historical gown prompted the Queen to ask her personal dresser, Angela Kelly, to make a replica. James was the first royal baby to wear the piece in 2008.
George (below in 2013) was also christened at the Chapel Royal, while Charlotte's took place at St. Mary Magdelene Church on the Queen's Sandringham estate in July 2015.