Irmgard of Oldenburg Peerage person ID=6392 Parents Adelheid von Tecklenburg Gerhard VI Children Onna Attena Siblings Adelheid von Oldenburg Gerhard Oldenburg Elisabeth of Oldenburg Dietrich Oldenburg Anna of Oldenburg Otto Oldenburg Hedwig Oldenburg John V Adolph, Count of Oldenburg-Delmenhorst Christian of Oldenburg Partners Hero Ommeken 'the Younger' zu Esens