The House of Habsburg (//; German: [ˈhaːpsbʊʁk]; alternatively spelled Hapsburg in English; German: Haus Habsburg), also officially called the House of Austria (German: Haus Österreich; Spanish: Casa de Austria), was one of the most influential and distinguished royal houses of Europe. The throne of the Holy Roman Empire was continuously occupied by the Habsburgs from 1440 until their extinction in the male line in 1740 and after the death of Francis I from 1765 until its dissolution in 1806.
The house also produced kings of Bohemia, Hungary, Croatia, Galicia, Portugal and Spain with their respective colonies, as well as rulers of several principalities in the Netherlands and Italy and emperors of Austria, Austria-Hungary and Mexico. From the 16th century, following the reign of Charles V, the dynasty was split between its Spanish and Austrian branches. Although they ruled distinct territories, they nevertheless maintained close relations and frequently intermarried including the House of Braganza of Pedro I, the first Emperor of Brazil and House of Habsburg of his wife, Empress Maria Leopoldina.
The house takes its name from Habsburg Castle, a fortress built in the 1020s in present-day Switzerland, in the canton of Aargau, by Count Radbot of Klettgau, who named 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. In 1273, Count Radbot's seventh generation descendant Rudolph of Habsburg became Roman-German King. He moved the family's power base to the Duchy of Austria, which the Habsburgs ruled until 1918.
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. In the 16th century, the family separated into the senior Spanish and the junior Austrian branches, who settled their mutual claims in the Oñate treaty.
The House of Habsburg became extinct in the male line in the 18th century. The senior Spanish branch ended upon the death of Charles II of Spain in 1700 and was replaced by the House of Bourbon. The remaining Austrian branch became extinct in the male line in 1740 with the death of Holy Roman Emperor Charles VI. It was succeeded by the descendants of his eldest daughter Maria Theresa's marriage to Francis III, Duke of Lorraine. The successor house styled itself formally as the House of Habsburg-Lorraine (German: Haus Habsburg-Lothringen). Since the House of Habsburg-Lorraine is referred to today as the House of Habsburg, historians use the appellation of the "Habsburg Monarchy" for the countries and provinces that were ruled by the family until 1918.
After the First World War, the House of Habsburg was a vehement opponent of National Socialism and Communism. In Germany, Adolf Hitler diametrically opposed the centuries-old Habsburg principles of largely allowing local communities under their rule to maintain traditional ethnic, religious and language practices, and he bristled with hatred against the Habsburg family. During the Second World War there was a strong Habsburg resistance movement in Central Europe, which was radically persecuted by the Nazis and the Gestapo. The unofficial leader of these groups was Otto von Habsburg, who campaigned against the Nazis and for a free Central Europe in France and the USA. Most of the resistance fighters, such as Heinrich Maier, who successfully passed on production sites and plans for V-2 rockets, Tiger tanks and aircraft to the Allies, were executed. The Habsburg family played a leading role in the fall of the Iron Curtain and the collapse of the Communist Eastern Bloc.
The Habsburg Empire had the advantage of size, but multiple disadvantages. There were rivals on four sides, its finances were unstable, the population was fragmented into multiple ethnicities, and its industrial base was thin. Its naval resources were so minimal that it did not attempt to build an overseas empire. It did have the advantage of good diplomats, typified by Prince Metternich; they had a grand strategy for survival that kept the empire going despite wars with the Ottomans, Frederick the Great, Napoleon and Bismarck, until the final disaster of the First World War. Along with the Capetian dynasty, its traditional rival house, it was one of the two oldest European royal dynasties and one of the most powerful as well, playing a key role in European politics for nearly five centuries.
The current house orders are the Order of the Golden Fleece and the Imperial and Royal Order of Saint George. The House of Habsburg still exists today and its members use the name Habsburg, such as the current head of the family Karl von Habsburg.