Habsburg Monarchy (Fiat Iustitia)

The Habsburg Monarchy or Empire (occasionally also styled as the Danubian Monarchy) is an unofficial appellation among historians for the countries and provinces that were ruled by the junior Austrian branch of the House of Habsburg. The Monarchy was a composite state composed of territories within and outside the Holy Roman Empire, united only in the person of the monarch. The dynastic capital was Vienna, except from 1583 to 1611, when it was moved to Prague.

The head of the House of Habsburg was often elected Holy Roman Emperor, although the two entities were never coterminous, as the Habsburg Monarchy covered many lands beyond the Holy Roman Empire, and most of the Empire was ruled by other dynasties. The Habsburg Monarchy did not usually include all the territories ruled by the Habsburgs. The senior branch ruled Spain until 1700, but it is not usually included in the definition of "Habsburg Monarchy" after the reign of Charles V, who divided the dynasty between its Austrian and Spanish branches upon his abdication in 1556.

The Habsburg family originated from the Habsburg Castle in modern day Switzerland, and after 1279 came to rule in Austria (known as "the Habsburg Hereditary Lands"). The Habsburg family grew to European prominence with the marriage and adoption treaty by Emperor Maximilian I at the First Congress of Vienna in 1515, and the subsequent death of adopted Louis II of Hungary and Bohemia in 1526.

Archduke Ferdinand of Austria, the younger brother of the Holy Roman Emperor Charles V, was elected the next King of Bohemia and Hungary following the death of Louis II of Hungary and Bohemia in the Battle of Mohács against the Turks.