The Duke and Duchess of Cambridge have named their new baby Prince Louis Arthur Charles.

The names honour both the Prince's grandfather, Prince Charles, and Louis Mountbatten, the Duke of Edinburgh's mentor who was killed by an IRA bomb in 1979.

Prince George and Prince William both have Louis as middle names, with the announcement confounding bookies and experts who had believed it would not be repeated for the third baby Cambridge.

Arthur had been the favourite predicted first name, eventually announced as a middle name. It is also one of the Duke of Cambridge's own middle names.

Kensington Palace said: "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."