Prince George of Cambridge's third given name, Louis, could to be a tribute to Lord Louis Mountbatten, the Duke of Edinburgh's uncle and the last British Viceroy of India before independence in 1947.
Lord Mountbatten and William's father, Prince Charles, were very close - he was Charles' confidant.
He was known by the royal family as Uncle Dickie and was assassinated by the IRA in August 1979.
Louis is also the Duke of Cambridge's fourth name - he is named William Arthur Philip Louis.
The latest addition to the royal family has been named Prince George Alexander Louis, but where did the Prince get his names?
The Duke and Duchess of Cambridge have named their son George Alexander Louis, Kensington Palace said.