 Llywelyn married Joan, natural daughter of King John of England, in 1205.Llywelyn and Joan had three identified children in the records but in all probability had more, as Llywelyn's children were fully recognized during his marriage to Joan whilst his father-in-law, King John, was alive.Little is known of Llywelyn's mistress, Tangwystl Goch, except that she was the daughter of Llywarch "Goch" of Rhos.