Real union is a union of two or more states, which share some state institutions; however they are not as unified as states in a political union. It has developed from personal union and usually was limited to monarchies.

Historical examples:

• Kalmar Union (1397?1524)
• Lublin Union (1569)
• Acts of Union 1707
• German Empire and Prussia between 1871 and 1918: The King of Prussia as an institution also was head of the empire, there under the title "German Emperor"

cs:Reálná unie de:Realunion hu:Reálunió pl:Unia realna pt:Uniăo real fi:Reaaliunioni