| Grand Duke of Ostland|
Großherzog von Ostland
House of Oberlander-Schwarzhelm
since June 4484
|Heir apparent:||Crown Prince Magnus Wilhelm|
|First monarch:||Ludwig I|
|Residence:||Wolfs Den (Wolfsheim)|
The Grand Duke of Ostland (Dundorfian: Großherzog von Ostland) is the monarch of the Grand Duchy of Ostland. The Grand Duke of Ostland is also entitled as the Prince of Touryou (Dundorfian: Prinz von Touryou; Kunikata: Touryou no ōji) of the Touryou State, the semi-autonomous area of Ostland that was granted autonomy by Grand Duke Magnus the Great.
The Grand Duke of Ostland was temporarily elevated to the "King of Ostland" by a collection of Eastern Land Council nobles who wished to push for a more radical agenda for the nation but were eventually arrested. The title of "Grand Duke" was returned shortly after their arrest.
- His/Her Ducal Highness, NAME, the Grand Duke of Ostland, Prince of Touryou (until 4556)
- His/Her Majesty, NAME, the Grand Duke of Ostland and Prince of Touryou (from 4556)