After days of speculation, Prince William and Kate Middleton have revealed the name of their new baby boy.

It was announced via the Kensington Palace Twitter account on Friday that the tot – who was born on Monday – has been called Louis Arthur Charles.

The message reads: “The Duke and Duchess of Cambridge are delighted to announce that they have named their son Louis Arthur Charles.

“The baby will be known as His Royal Highness Prince Louis of Cambridge.”

Louis is a special name in the Royal Family and has already been used as one of his older brother Prince George’s middle names. It’s also one of William’s names too, as is Arthur.

Presumably Louis is a reference to Prince Charles’ much-loved great uncle Louis Mountbatten too, the uncle of Prince Phillip who was assassinated in 1979.

Meanwhile the new Louis’ final middle name, Charles, is clearly in honour of his granddad Prince Charles, so all three names are very meaningful to the family.

The name quickly started trending on Twitter after being announced and many fans seem to like it.

“very cute even though i was rooting for arthur as a first name,” one social media user commented, whilst another wrote: “I love it, it’s such a lovely classy name”

And one added: “I love it! Welcome to the world Prince Louis Arthur Charles”

The name comes as quite a surprise after the bookies picked Alexander and Albert as favourites.

Prince William sparked speculation that his newborn son had been named Alexander with a comment he made at Westminster Abbey’s Anzac Day service on Wednesday.

When Alexander Downer, the Australian High Commissioner, said that he thought his name would be a good choice, William teasingly replied: “Funny you should say that… It’s a good name.”

Little Louis was born on Monday at the Lindo Wing of London’s St Mary’s Hospital and weighed in at 8lbs 7oz.

Welcome to the world, Prince Louis!