The Duchy of Normandy was created in the year 911, alot of the creation also stemming over to the year 912.
The French surname of Dubuque is first found in early records of Normandy, the former Duchy of Normandy.
Duchy of Żagań was created in 1274.
Duchy of Friedland was created in 1627.
Duchy of Burgundy was created in 843.
Duchy of Carinthia was created in 976.
Duchy of Carniola was created in 1364.
Duchy of Florence was created in 1532.
Duchy of Friuli was created in 569.
Duchy of Głogów was created in 1177.
Duchy of Warsaw was created in 1807.
Duchy of Brzeg was created in 1311.
Duchy of Belz was created in 1170.