In advance of Monday's birth, the British bookies had made George the odds-on favourite if the baby was a boy, and it is a name with deep royal resonance.
The most recent high-profile royal George is King George VI, Queen Elizabeth's late father.
He had the given names Albert Frederick Arthur George, but took his fourth moniker — George — as his regal name, in a respectful nod to his father, King George V.
George VI served as king from 1936, after the abdication crisis sparked by his elder brother Edward VIII, until his death in 1952.
His reign also lives on in popular culture because of the movie The King's Speech, a 2010 film that went on to win Oscars for best picture and best actor for Colin Firth.
"If the royal baby is named George, the public is going to think of King George the Sixth, especially with the film The King's Speech having been so successful," said Carolyn Harris, a Toronto-based royal historian and blogger.
The BBC is reporting that Alexander "was said to be a favourite" name of Kate's; and there is the possibility that this becomes the name that he is known by in family circles. But it is a name that also has echoes in British history.
"There were three kings of Scotland in the Middle Ages named Alexander," Harris said in an interview earlier this year.
At the time, much royal baby name speculation had focused on Alexandra for a girl, and Harris was making the point that "naming a royal baby Alexandra would reinforce the Crown's connections to Scotland" at a key moment in British history when Scotland is debating devolution.
Other echoes of Alexander go back to the time of Queen Victoria, whose first name was actually Alexandrina, in a nod to her godfather, Alexander I of Russia.
As well, Queen Elizabeth's second name is Alexandra.
While no British monarch has reigned under the name of Louis, that moniker has a special family significance within the House of Windsor.
Little Prince George's great-grandfather, Prince Philip, the Duke of Edinburgh, was particularly close to his uncle, Lord Louis Mountbatten, a prominent British statesman and naval officer who was the last viceroy of India leading up to its independence.
Mountbatten, who died when the IRA blew up his yacht off the coast of Ireland in 1979, was also a close confidante and important figure in the life of the new prince's grandfather, Prince Charles.
Louis also has echoes within Prince William's full name: William Arthur Philip Louis.
Just three monikers
Prince George's name does veer from recent royal tradition in some respects: it has only three components, unlike the four of his father and grandfather (Charles Philip Arthur George).
There is also no direct nod to the baby's father or grandfather, a common practice in royal names.
As well, Prince George's name became public in relatively quick order, compared with that of his father or grandfather. William's name was announced six days after his birth in 1982. Prince Charles's name was made public a month after his birth in November 1948.
As history would have it, the most recent Prince of Cambridge, who lived from 1819 to 1904, was also George.
But his life was rather complicated — at least personally — with illegitimate children and mistresses, and the new Prince George may not wish to emulate his predecessor too much if he becomes concerned about his reputation.
The last Prince George "was a complicated character who ended up living his life on his own terms rather than following the expectations of a royal prince at that time in terms of his personal life," Harris notes.
George ran into royal trouble with his 1837 marriage to Sarah Fairbrother, a woman who had several strikes against her as a possible royal wife at that time.
"He had a very complicated legacy as he was one of the numerous members of the royal family who was affected by the Royal Marriages Act," says Harris.
Fairbrother was the daughter of a servant at Westminster, and had been an actress for 10 years: a background that would have been common for royal mistresses of that era but not considered suitable for a royal wife.
She and George had two children together prior to their marriage, and another son after. But that son could not inherit his father's title because George's marriage wasn't considered legal and the then dukedom of Cambridge died with him.