The House takes its name from Habsburg Castle, a fortress built in the 1020s in present-day Switzerland by Count Radbot of Klettgau, who chose to name his fortress Habsburg. His grandson, Otto II, was the first to take the fortress name as his own, adding "Count of Habsburg" to his title. The House of Habsburg gathered dynastic momentum through the 11th, 12th and 13th centuries.
A series of dynastic marriages enabled the family to vastly expand its domains, to include Burgundy, Spain and its colonial empire, Bohemia, Hungary, and other territories into the inheritance. In the 16th century; the family separated into the senior Habsburg Spain and the junior Habsburg Monarchy branches, who settled their mutual claims in the Oñate treaty.
The House of Habsburg became extinct in the 18th century. The senior branch ended upon the death of Charles II of Spain in 1700 and was replaced by the House of Bourbon. The remaining branch went extinct in the male line in 1740 with the death of Holy Roman Emperor Charles VI and completely in 1780 with the death of his eldest daughter, Maria Theresa of Austria. It was succeeded by the Vaudemont branch of the House of Lorraine. The new successor house styled itself formally as House of Habsburg-Lorraine (German: Habsburg-Lothringen), although it was often referred to as simply the House of Habsburg.
The House of Habsburg-Lorraine
On August 6, 1806 the Holy Roman Empire was dissolved under the French Emperor Napoleon I's reorganization of Germany. However, in anticipation of the loss of his title of Holy Roman Emperor, Francis II declared himself hereditary Emperor of Austria (as Francis I) on August 11, 1804, three months after Napoleon had declared himself Emperor of the French on May 18, 1804.
On November 11, 1918, with his empire collapsing around him, the last Habsburg ruler, Charles I (who also reigned as Charles IV of Hungary) issued a proclamation recognizing Austria's right to determine the future of the state and renouncing any role in state affairs. Two days later, he issued a separate proclamation for Hungary. Even though he did not officially abdicate, this is considered the end of the Habsburg dynasty. In 1919, the new republican Austrian government subsequently passed a law banishing the Habsburgs from Austrian territory until they renounced all intentions of regaining the throne and accepted the status of private citizens. Charles made several attempts to regain the throne of Hungary, and in 1921 the Hungarian government passed a law which revoked Charles' rights and dethroned the Habsburgs.
The Habsburgs did not formally abandon all hope of returning to power until Otto von Habsburg, Emperor Charles' eldest son, renounced all claims to the throne.
The dynasty's motto, "Leave the waging of wars to others! But you, happy Austria, marry; for the realms which Mars awards to others, Venus transfers to you.",indicates the knack of the Habsburgs to have members intermarry into other royal houses in order to build alliances and inherit territory. Empress Maria Theresa is recognized quite notably for it and is sometimes referred to as the "Great-Grandmother of Europe".