to naught in the Irish War of Independence. Later historians have used the term to refer to other examples where one king ruled two states, such as Henry V and Henry VI, who were effectively kings of both England and France in the fifteenth century as a result of the formation of a puppet state in a large area of France during the Hundred Years' War, Denmark–Norway, a dual monarchy that existed from 1537 to 1814, a century of personal union of Sweden and Norway (1814-1905), the Iberian Union between Portugal and Spain (1580–1640), and the Polish–Lithuanian Commonwealth (1569–1795). A dual monarchy is a stronger bond than a personal union, in which two or more kingdoms are ruled by the same person but there are no other shared government structures. States in personal union with each other have separate militaries, separate foreign policies and separate customs duties. In this sense Austria-Hungary was not a mere personal union, as both states shared a cabinet that governed foreign policy, the Army and common finances. See also Iberian Union (1580–1640) Austria-Hungary (1867–1918) Kingdom of Hejaz and Nejd (1926–1932) Union of the Crowns (1603-1707) References Politics of Austria-Hungary Monarchy Political systems Iberian Union