The name is derived from the Swiss Habichtsburg (Hawk Castle), the family seat in the 12th and 13th centuries at Habsburg, Switzerland. From South-East-Germany the family extended its influence and holdings to the eastern reaches of the Holy Roman Empire, roughly today's Austria (1278–1382). Within only two or three generations, the Habsburgs had managed to secure an initially intermittent grasp on the imperial throne that would last for centuries (1273–1291, 1298–1308, 1438–1740, and 1745–1806).
After the marriage of Maximilian I with Mary, heiress of Burgundy (the Low Countries) and the marriage of his son Philipp the Handsome with Juana, heiress of Spain and its newly-founded empire, Charles V inherited an empire where "the sun does not set".
The Spanish Habsburgs died out in 1700 (prompting the War of the Spanish Succession), as did the Austrian Habsburgs in 1740 (prompting the War of the Austrian Succession). However, the heiress of the last Austrian Habsburg (Maria Theresa) had married Francis Stephen Duke of Lorraine, and their descendants carried on the Habsburg tradition from Vienna under the dynastic name Habsburg-Lorraine. It is speculated that extensive intra-family marriages within both lines contributed to their extinctions.
In 1806 the Holy Roman Empire was wound up under the French Emperor Napoleon I's reorganisation of Germany. However, in anticipation of the loss of his title of Holy Roman Emperor, Francis II declared himself hereditary Emperor of Austria in 1806, two years after Napoleon declared himself Emperor of France in 1804. (The dates are a bit doubtful here.)
Hungary, nominally under Habsburg kingship from 1526 but mostly under Ottoman Turkish occupation for 150 years, was reconquered in 1683–1699. In 1867 effective autonomy was given to Hungary under the terms of the Ausgleich or "compromise" (seeAustria-Hungary) until the Habsburgs' deposition from both Austria and Hungary in 1918 following defeat in World War I.
The current head of the Habsburg family is Otto von Habsburg, Emperor Karl's eldest son.