The House of Austrian Habsburgs came into being after the April 21, 1521 assignment of the Austrian lands to Ferdinand I from his brother Emperor Charles V (also King Charles I of Spain) (1516 - 1556). This split the Habsburg family into the Spanish Habsburgs and the Austrian Habsburgs. The Austrian Habsburgs held (after 1556) the title of Holy Roman Emperor, as well as the Habsburg Hereditary Lands and the Kingdoms of Bohemia and Hungary.
Technically, The Austrian Habsburgs died out in 1740 (prompting the War of the Austrian Succession). However, the heiress of the last Austrian Habsburg (Maria Theresa) had married Francis Stephan Duke of Lorraine, and their descendants carried on the Habsburg tradition from Vienna under the dynastic name Habsburg-Lorraine.