Duchy of Montferrat was created in 1574.
Duchy of Montferrat ended in 1708.
March of Montferrat was created in 961.
Duchy of Racibórz was created in 1172.
Duchy of Westphalia was created in 1180.
Duchy of Bielsko was created in 1572.
Duchy of Głubczyce was created in 1172.
Duchy of Zator was created in 1454.
Duchy of Limburg was created in 1065.
Duchy of Friuli was created in 569.
Duchy of Żagań was created in 1274.
Duchy of Württemberg was created in 1495.
Duchy of the Archipelago was created in 1207.