Austrian Empire (1804-1867) / Austro-Hungarian Empire (1867-1918), Constitutional Monarchy 1867-1918








Kingdom of Denmark, Constitutional Monarchy since 1849



Uncertain:
Succession 1848-1852





Kingdom / Empire of France, Constitutional Monarchy 1814-1870





Second French Republic
1848-1852



German States: Kingdom of Bavaria, Constitutional Monarchy 1818-1918








German States: Kingdom of Hanover, Constitutional Monarchy 1833-1866







German States: Kingdom of Prussia (1701-1918) / German Empire (1871-1918), Constitutional Monarchy 1848-1918






German States: Kingdom of Saxony, Constitutional Monarchy 1831-1918









German States: Kingdom of Württemberg, Constitutional Monarchy 1819-1918









United Kingdom of Great Britain and Ireland, Constitutional Monarchy since 1688










Kingdom of Greece (1832-1924), Constitutional Monarchy 1843-1924





Italy: Kingdom of the Two Sicilies (1816-1861), Absolute Monarchy => Kingdom of Italy






The Kingdom of the Two Sicilies and the Kingdom of Sardinia were merged to form the new Kingdom of Italy (1861-1946)

Italy: Kingdom of Sardinia (1720-1861), Constitutional Monarchy 1848-1861 => Kingdom of Italy





The Kingdom of the Two Sicilies and the Kingdom of Sardinia were merged to form the new Kingdom of Italy (1861-1946)
 

Kingdom of Italy (1861-1946), Constitutional Monarchy 1861-1928, 1943-1946



Uncertain:
Succession 1900-1904


Kingdom of Portugal and the Algarves (1139-1910), Constitutional Monarchy 1822-1910



Uncertain:
Succession 1826-1837








Kingdom of Spain, Constitutional Monarchy 1812/1834-1873, 1874-1931







First Spanish Republic
1873-1874