Margareta of Opava-Ratibor Duchess of Rawa (1410–1459) Parents John II, Duke of Opava-Ratibor Helena Korybutówna Children Margareta of Rawa Siblings Wenceslaus II, Duke of Opava-Ratibor Nicholas V, Duke of Krnov Partners Casimir I of Oświęcim Siemowit V of Masovia