dual monarchy
General term for a political entity where two separate kingdoms are ruled by the same monarch, while retaining their own laws and institutions.
The concept of a dual monarchy is often discussed alongside the history of the Austro-Hungarian Empire.
Austria-Hungary; Austro-Hungarian Empire
Specifically refers to the historical Austro-Hungarian Empire (1867–1918).
See also: オーストリアハンガリー帝国
The Dual Monarchy was dissolved after World War I.
More common and direct name for the Austro-Hungarian Empire; 二重帝国 is a historical/political term emphasizing the dual structure.
Compound of 二重 (double, dual) and 帝国 (empire). The term is a direct translation of the Western political concept of 'dual monarchy' and is used primarily in historical contexts.