Prince Louis is the youngest child of Prince William and Princess Kate – and much like his siblings was given more than one name at birth.

When Prince Louis’ full name was announced five days after his birth, the choice surprised many.

Louis had not been high amongst bookmakers’ predictions, with seemingly the only existing connection to the name coming in the form of King Charles’ great uncle and mentor, Lord Mountbatten, who was named Louis.

The name also does not have a strong royal history in the same way that his older brother’s name does, given six Kings in British history have, so far, used the name George.

On the other hand, Louis’s middle name Arthur had been the favourite among bookies to be chosen as the baby’s first name.

Unlike Louis, Arthur does have a strong pedigree. It was the name given by Henry VII to his first-born son, who died before he could claim the throne, meaning that Henry VIII became King upon his father’s death.

It was the name of the famous medieval legend, although historians dispute the existence of any King Arthur in British history.

Most historians concur that the myth is based on a number of leaders in England and France prior to the conquest which eventually became encapsulated in a number of translated texts.

King Arthur appeared in several books from around the 12th century with the famous image of Arthur pulling a sword out of a stone coming from Thomas Malory’s 15th century Le Morte d’Arthur.

Arthur was, therefore, a logical choice for the Wales’s second-born son, although in reality, the real meaning behind the choice might not be the one commonly understood.

The name was one of the middle names of King George VI, the father of Queen Elizabeth II and Louis’ great-great-grandfather.

This may have been the real reason underpinning the choice of middle name, a mark of respect to the late Queen’s father with whom she shared a close bond.