The Queen was forced to intervene and change Prince Louis' official name after a longstanding rule created by King George V in 1917 would have stopped him having an HRH title.
After Prince William and Kate Middleton welcomed their third child to the family on April 23, 2018, the proud new parents named him Louis Arthur Charles.
As the third of their children, they chose Louis as a name in honour of Prince Charles 's mentor Lord Louis Mountbatten, who died in an IRA bombing in 1979.