Under Charles V (r. 1519–1556), the empire reached its greatest territorial extent, functioning as the primary defender of Catholicism against the Ottoman Empire and the burgeoning Protestant Reformation. The Long Pivot: Division and Absolutism
The dynasty's prominence began when Rudolf I was elected King of the Germans in 1273. By 1282, the family secured the Duchy of Austria, making Vienna their administrative heart.
This brought the wealthy Low Countries (modern Belgium and the Netherlands) into the fold.
The Habsburg Empire was a cornerstone of European geopolitics for over 600 years, evolving from a modest Swiss lordship into a global superpower that "the sun never set upon" before its final dissolution after World War I. Its history is a complex tapestry of strategic marriages, religious upheaval, and the eventual collision with 20th-century nationalism. The Rise: "Let Others Wage War; You, Happy Austria, Marry"
While many empires grew through conquest, the Habsburgs famously expanded through strategic alliances and inheritance.
The famous motto Bella gerant alii, tu felix Austria nube defined their ascent. Key unions included: