Otto of Plain and Hardegg Count of Plain and Hardegg, died 1260 during the battle of Staatz (1300–1260) Parents Berta Konrad I, Graf von Plain und Hardegg Children Siblings Konrad of Plain and Hardegg Agnes, Gräfin von Plain und Hardegg Partners Willbirg (Wilbirg, Wilpirg) of Helfenstein