In some far distant land of the past, it is possible that Kate Middleton and the Fanning sisters (Dakota, Elle) had a common ancestor: King Edward I, known as Longshanks. He was King of England from 1272 to 1307. This makes the women 21st cousins, reports People. Michelle Ercanbrack, a family historian for Ancestry.com, said of Elle, “You can consider her a long-lost princess.” Sure. Long-lost Princess Longshanks.