Duchy of Ferrara was created in 1264.
Duchy of Ferrara ended in 1597.
University of Ferrara was created in 1391.
Ferrara Marathon was created in 1979.
Ferrara Bible was created in 1553.
Duchy of Racibórz was created in 1172.
Duchy of Silesia was created in 1163.
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.