Royal baby boy ‘likely to be called James, George or Henry’, as it’s revealed he’s the heaviest future king in 100 years

Philip and Francis also viable options for the royal baby name, which has yet to be announced by Kate Middleton and Prince William

Kate Middleton is likely to name the royal baby boy James, George or Henry, according to a top royal author.

The Duchess of Cambridge will stick to traditional names for the Prince of Cambridge, who’s replacing Prince Harry as third in line to the throne.

Catherine gave birth to her son at 4.24pm at St Mary’s Hospital in London yesterday – weighing in at a heavier than average 8lbs 6oz.

The Duke and Duchess of Cambridge aren’t thought to have known the sex of the baby before the birth and no name has yet been announced.

But royal babies mostly have traditional names that are passed down through generations – with experts reckoning Prince William, 31, stick to this option.

George and James are the bookies favourites for the royal baby boy – although Francis, Charles and Philip are also likely options.

"I do think that Prince William is quite a traditionalist - that's my feeling," said Charles Kidd, editor of Debrett's Peerage and Baronetage.

"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."

He suggested that George – currently the bookies favourite at 5/2 – could be their baby name of choice.

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There’s been six King Georges on the throne in England and the name itself has come to symbolize the continuation of the monarchy.

The most recent King George to rule was the late Queen mother’s husband Prince Albert, who used his fourth name George as his Sovereign name.

James – the name of Kate’s younger brother – is the bookies favourite at Ladbrokes at 2/1. There’s been two King James in the past, but it’s also the name of one of William’s cousins so it’s less likely they’ll choose this.

Henry, the true name of William’s brother Prince Harry, is also in the running at currently 5/1 – and Philip and Francis are viable options too.

The royal baby name news comes as it was revealed that weighing in at 8lbs 6oz, he’s a little heavier than the average newborn.

He’s actually the heaviest future king for 100 years, weighing more than 1lb heavier than both Harry and William.

And unlike the Prince of Cambridge, the majority of babies born in the capital are born out of wedlock – with only 36 per cent of London babies born to married parents.

The rate of babies born to married parents in the Borough of Westminster – where the royal baby boy was born – is even lower at 25 per cent.

The most common names for babies in London are Daniel and Isabella, but we can’t see the royal couple opting for such a modern name.

We’re rooting for Francis – it’s traditional, yet something a bit different. Besides, HRH Prince Francis of Cambridge has quite a ring to it, doesn’t it?

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Tell us what you think the couple will call the royal baby boy over on Twitter now.