Europe[]
- Germany [Presidential republic]
- United Kingdom [Constitutional monarchy]
- France [Semi-presidential republic]
- Belgium [Constitutional monarchy]
- Italy [Constitutional monarchy]
- Union of Soviet Socialist Republics [Federative socialist republic]
- Central European Confederacy [Confederation]
- Spain [Constitutional monarchy]
- Denmark [Constitutional monarchy]
- Sweden [Constitutional monarchy]
- Norway [Constitutional monarchy]
- Kingdom of Yugoslavia [Absolute monarchy]
- Greece [Constitutional monarchy]