After the brief speech, the Queen joined the rest of the royals up on the palace balcony to watch nearly 100 aircraft, from Second World War Spitfires to the newest stealth fighter jet, fly over the palace.
Louis was baptised by the Archbishop of Canterbury, the Most Reverend Justin Welby in a 40-minute service which started at 4 pm, and was attended by royals including William's brother Prince Harry and his new wife Meghan, Duchess of Sussex.
Members of the royal family tilted their heads skyward on Tuesday afternoon as the Royal Air Force marked its centenary with a dramatic flypast across central London and over Buckingham Palace. Carter is a college friend of Kate's, and she and her husband Robert live in the county of Norfolk near Anmer Hall, William and Kate's country home.
Meghan's odds are 14/1, while Kate's sister Pippa Matthews is 10/1.
Prince Louis Arthur Charles of Cambridge has been christened, marking his first public event since his birth on April 23.
Other videos from the christening show Charlotte and her family greeting a priest at the Chapel Royal in St. James's Palace. Think about it: have you ever seen Kate Middleton with a hair out of place?
Royal observes also believe that Kate's decision to wear white or cream at the Christening of Prince George, Princess Charlotte, and now Prince Louis is because the colours perfectly complement the Royal Christening gown, worn by all three children.
The service is due to start at 1500 GMT (11pm Monday Singapore time) and last 40 minutes, while the list of godparents is expected later on Monday.
At this point, it's safe to say that Kate Middleton has definitely noticed that Meghan Markle is giving her a good run for her money, at least when it comes to media attention. While Harry also wore a blue suit and light blue tie, Meghan opted for an olive Ralph Lauren dress with a matching headpiece and Manolo Blanik pumps.