The Duke and Duchess of Sussex have broken with royal convention by refusing to give their new son Archie a title.
As the first born son of a duke, Archie could have become Earl of Dumbarton - one of Harry's subsidiary titles - or have been Lord Archie Mountbatten-Windsor.
Instead he will simply be known as Master Archie Mountbatten-Windsor.
A source said: "They have chosen not to use a courtesy title."
The decision fits in with Harry and Meghan's desire to give their son as normal a life as possible despite his royal heritage.
Harry, who has admitted he once "wanted out" of the royal family, has spoken in the past of how he was always more comfortable being Captain Wales in the Army than being Prince Harry.
The new baby's full name is Royal baby name REVEALED by proud Meghan Markle and Prince Harry Harrison Mountbatten-Windsor.
Archie means "genuine", "bold" and "brave", and is German in origin.
Short for Archibald, it is now given as a name in its own right.
Harrison means "son of Harry" so is likely to be a tribute to the duke.
Royal baby name REVEALED by proud Meghan Markle and Prince Harry
Archie is not entitled to be an HRH or a prince due to rules set out more than 100 years ago by George V.
The youngster was taken to meet the Queen on Wednesday. Harry and Meghan were joined by her mother, Doria Ragland and the Duke of Edinburgh at Windsor Castle as the monarch got a first glimpse of her latest great grandchild.
The couple's @SussexRoyal Instagram account announced: "The Duke and Duchess of Sussex are pleased to announce they have named their first born child: Archie Harrison Mountbatten-Windsor
"This afternoon Their Royal Highnesses introduced Her Majesty The Queen to her eighth great-grandchild at Windsor Castle. The Duke of Edinburgh and The Duchess' mother were also present for this special occasion."
Harry and Meghan's first born, who is seventh in line to the throne, made his world debut with his besotted parents at Windsor Castle on Wednesday.
Proud mother Meghan described him as having the "sweetest temperament", while a delighted Harry called him "our own little bundle of joy".
The duchess added: "It's magic, it's pretty amazing. I have the two best guys in the world so I'm really happy."
As is the custom for royal babies, Harry and Meghan will have shared news of their choice with the monarch before releasing it to the public.
The duke and duchess's son arrived overdue on Monday May 6 at 5.26am, weighing 7lb 3oz.
Among the bookmakers' favourites were Alexander, Arthur, Albert, as well as James and Philip, while Spencer was a late favourite, but Archie was a surprise choice.
