Before revision: Johann Freiherr von O'Brien, Earl of Thomond (1775 – 1830), was an Austrian Major General with Irish ancestry, most noted for leading an action in Jedlesee, 1809, near Vienna, against a superior force of Napoleon's troops in preparation for their defeat by Archduke Charles in the Battle of Aspern.
After revision: Johann Freiherr von O'Brien, Earl of Thomond (1775 – 1830), was an Austrian Major General with Irish ancestry, most noted for leading an action in Jedlesee, 1809, north ofthe Battle of Schwarze Lackenau near Vienna, against a superior force of Napoleon's troops in preparation for their defeat by Archduke Charles in the Battle of Aspern.