The Duke and Duchess of Sussex have named their baby Archie Harrison Mountbatten-Windsor.

The couple announced the name on Wednesday in an Instagram post that showed other members of the royal family meeting the newborn.

The caption read: “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."

The Daily Mail correspondent Rebecca English first reported that Archie won't have a royal title and will be known as "Master Archie." The Palace confirmed to INSIDER that Archie would not have a royal title.

Prince Harry and Meghan Markle welcomed the baby boy, who weighed 7 pounds, 3 ounces, at 5:26 a.m. on Monday.

Archie made his debut on the grounds of Windsor Castle on Wednesday.

The duke and duchess opted out of the traditional hospital photo-op and instead waited until two days after the birth to give the world a glimpse of their newborn.

Read more: Meghan Markle broke a major royal baby tradition followed by Kate Middleton and Princess Diana

The significance and meaning of the name 'Archie Harrison'

The name Archie, which started as a shortened form of Archibald but has been used alone since the 19th century, has seen a rise in popularity in the past decade, according to BritishBabyNames.com.

Its roots appear to be Scottish, meaning "genuine and bold." It can also mean "bald" when referring to the shaven head of a monk, and was introduced in England during the Norman Conquest in the 11th Century.

Baby Sussex

Foto: Archie Harrison Mountbatten-Windsor.sourceDominic Lipinski/ AFP/ Getty Images.

As well as being the name of a red-headed cartoon character, Archie has been used as a nickname for Prince George, previous reports suggested.

Harrison, a common English name, means "son of Harry."

While it is unclear if there is any deep tie to the name Archie, a friend of Prince William's, Archie Soames, was an usher at the wedding where Harry and Meghan made one of their first appearances together in 2017.

Soames, like William and Harry, studied at Eton. He is the great-grandson of Sir Winston Churchill and believed to be a close confidant to Prince William, according to the MailOnline.

The UK betting company Ladbrokes had listed Spencer (3-10), Alexander (5-1), and Arthur (6-1) as the top contenders before the name was announced on Wednesday.

Others thought Harry and Meghan would opt to return to tradition with Albert, Charles, or Edward, the most popular male names for royals.

The Duke and Duchess are keeping their birth more private than the royal family has in the past

The couple announced Archie's arrival with a heartfelt Instagram post on Monday.

"We are pleased to announce that Their Royal Highnesses The Duke and Duchess of Sussex welcomed their firstborn child in the early morning on May 6th, 2019. Their Royal Highnesses' son weighs 7lbs. 3oz," the post read.

"The Duchess and baby are both healthy and well, and the couple thank members of the public for their shared excitement and support during this very special time in their lives."

Harry and Meghan previously announced plans to keep the details surrounding the birth "private."

Read more: Prince Harry and Meghan Markle's son may have dual citizenship, but it won't be granted at birth

A statement released by Buckingham Palace last month said: "The Duke and Duchess of Sussex are very grateful for the goodwill they have received from people throughout the United Kingdom and around the world as they prepare to welcome their baby.

"Their Royal Highnesses have taken a personal decision to keep the plans around the arrival of their baby private. The Duke and Duchess look forward to sharing the exciting news with everyone once they have had an opportunity to celebrate privately as a new family."