Cymburgis, also Cimburgis, Cimburga or Cymbarka of Masovia (born 1394 or 1397 in Warsaw; died September 28, 1429 in Türnitz , Lower Austria) from the Piast dynasty, was the wife of Ernest the Iron and thus a Duchess of Austria from of the Styrian-Inner Austrian line.
As the mother of Emperor Frederick III she became the ancestor of all later Habsburgs, as only his line of the family survived. She brought the famous Habsburg lip into the family, a particular physical characteristic of most members of the family for many generations until the 18th century. It can even be recognized in some of her distant descendents today (yet not quite is strongly), e.g. in King Juan Carlos I of Spain.