While the couple didn’t choose a name to reflect Prince Philip, they did select a name that directly honors Prince Harry’s grandmother — Queen Elizabeth II, and its origin dates back decades. According to the BBC, when Elizabeth was very young, she had trouble pronouncing her own name, as is common with small children — particularly with a multisyllabic moniker like Elizabeth. Her grandfather, King George V, found her mispronunciation charming, and began calling her Lilibet out of affection. 

The name stuck, and the queen is still called Lilibet by her family. Her late husband even used the nickname, writing to his mother-in-law shortly after their wedding, “Lilibet is the only ‘thing’ in the world which is absolutely real to me.”

Prince Harry and Meghan Markle’s baby girl has a middle name that is also very significant — Diana. Princess Diana, of course, was Prince Harry’s mother, who died an untimely death when the prince and his brother were young. 

As to the mouthful of the hyphenated last name, that has historical context as well. According to Time, the royal family’s official surname has been Mountbatten-Windsor for a long time. When the queen was born, the royal family name was simply ‘Windsor,’ but she had it officially changed in 1960 to make use of her husband’s family name.