The Duke and Duchess of Cambridge are expected to pick a traditional royal name for their newborn baby prince.
Royal infants mostly have historical names which are passed down through the generations.
Charles Kidd, editor of Debrett's Peerage and Baronetage, predicts William and Kate will select a conventional first name for their son.
"I do think that Prince William is quite a traditionalist - that's my feeling," Mr Kidd said.
"The fact that he chose to use the royal dukedom (of Cambridge) and has followed royal precedent, I wouldn't be surprised if they use a name that is already familiar in the royal family - something that has royal associations."
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He suggested that George - a favourite at the bookmakers - could be their name of choice.
There are also predictions the couple will honour William's father the Prince of Wales by choosing Charles and the Duke of Edinburgh by selecting Philip.
Midway through her pregnancy, Kate revealed she and William had a shortlist of names and that her friends were giving her ideas.
"We have a shortlist for both (boy and girl) but it's very difficult. My friends keep texting me names," she told a well-wisher.
The baby, which will eventually be king, will be styled HRH Prince (forename) of Cambridge. Should he require a surname, such as on marriage, it will be Mountbatten-Windsor.
One day the baby is also likely to become the Prince of Wales. The title is usually given to the male heir to the throne, but it is not automatic.
Royal babies also usually have a number of middle names. The Prince of Wales has four names, as does William.
