Duchy of Holstein ended in 1866.
Duchy of Holstein was created in 1474.
Peter III, Czar of Russia (1762), was born 21 February 1728 in Kiel, the former duchy of Holstein-Gottorp, now Schleswig-Holstein, Germany.
Duchy of Urbino ended in 1625.
Duchy of Carniola ended in 1918.
Duchy of Friuli ended in 828.
Duchy of Florence ended in 1569.
Duchy of Württemberg ended in 1806.
Duchy of Brzeg ended in 1675.
Duchy of Belz ended in 1462.
Duchy of Teschen ended in 1918.
Duchy of Lithuania ended in 1413.
Duchy of Merania ended in 1248.