In the earliest times, what is now the duchy of A. was inhabited by the Taurisci, Celtic people; but their name subsequently disappeared before that of the Norici. After the conquest of the Norici by the Romans (14 n.c.), the country to the n. of the Danube belonged to the kingdom of the Marcomanni (q.v.); on the s. of the river lay the Roman provinces of Noricum and Pannonia, in which last was the municipal city of Vindo bona (Vienna). Tyrol formed part of lihretia. All these boundaries were swept away by the irruption of the northern peoples; and the regions in question were occupied in succession, during the 5th and 6th centuries, by Bon_Vandals, Goths, Huns, Lombards, and Avari. After the Lombards had settled in Italy, the Ens came, about 568, to be the boundary between a tribe of German origin and the Avari, II people who had pene trated thither from the east. The Avari having, in 788, crossed the Ens, and fallen upon Bavaria, then part of the Frankish empire, Charlemagne drove them back (796) as far as the Raab, and united the district from the Ens to that river with Germany, under the name of the East Mark, Marchia Orientalis, or Austria. He sent colonists, mostly Bavarians, into the new province. and appointed over it a margrave. It came into the possession of the Hungarians in 900, but was reconquered by Otto I. in 955, and reunited with Germany.
As margrave of the reeonquered province, the emperor, in 9S3, appointed Leopold of Babenberg (q.v.), whose dynasty ruled A. for 260 years. Under Henry Jasomirgott (1141-1177), the mark above the Ens was annexed to the lower mark, the united province raised to a duchy, and important privileges conferred on the newly named duke and his heirs. This Henry Jasomirgott took part in the second crusade; he also removed the ducal residence from Leopoldsberg to Vienna, now first called a city, and began the building of the cathedral of St. Stephen. Under his successors, numerous additions (Styria, Carniola) were made to the possessions of the house. Leopold VI. undertook numerous expeditious hgainst the Hungarians and the infidels, and is reckoned the best of the Bahenberg princes. The line became extinct with his successor, Frederick, who fell in battle with the Magyars (1246).
Then followed an interregnum from 1246 to 1282. The emperor Frederic II. at first treated the duchy as a lapsed fief of the empire; shortly, claims were set up by Count Hermann of Bavaria, who was married to a niece of the deceased marerave, Frederic; and when Hermann died, and the empire was distracted by the. contests between rival emperors, the "states" of A. and Styria chose Ottokar, son of the Bohemian king, as duke, who made good his nomination about 1260. Ottokar, refusing to acknowl edge Rudolf of Hapsburg as emperor, was defeated, and lost his life and possessions, in the battle of Marchfeld (1278); and the emperor shortly afterwards (1282) conferred the duchies of A., Styria, and Carinthia on his son Albrecht.
The accession of the Hapsburg dynasty With Albrecht I. (q.v.) was the foundation of A.'s subsequent greatness. The despotic Albrecht contended successfully with Hun garians and Bavarians, but while attempting to subdue the Swiss, he was murdered near Rheinfelden (1308) by his nephew, John of Swabia, whom he had deprived of his heredi tary possessions. Of his 5 sons, Frederic was chosen (1314) by a party to the imperial throne, but was defeated (1322) by his rival, Ludwig of Bavaria. Duke Leopold was defeated at Morgarten (1315)in his attempt to reduce the Swiss cantons that had thrown off their allegiance to Albrecht I. At last, by the death of all his brothers, Albrecht II. reunited the Austrian possessions, increased by various additions. After his death (1358), two sons, Rudolf and Albrecht III., successively followed in the duchy of Austria. Another son, Leopold, held the other lands, but lost his life at Sempach, in seeking to regain the Hapsburg possessions in Switzerland. The posterity of Albert and Leopold formed the two lines of A. and Styria. During Albrecht ill's reign, Tyrol and other districts were ceded to Austria. After his death (1395), the dukedom was held by his son, Albrecht IV. Albrecht V., who succeeded his father in 1404, by marrying the daughter of the emperor Sigismund, succeeded ((1438) to the thrones of Hungary and Bohemia, and was at the same time raised to the dignity of German emperor, as Albrecht IL With his death, in 1439, Bohemia and Hungary were for a time lost to the house of A., a-s were also, after a bloody struggle, the last of the family possessions in Switzerland. But the imperial dignity was henceforth uninterruptedly held by them. With Ladislaw, Albrecht's son, the Austrian line of the house closed (1457), and their possessions went to the Styrian line. Of this line was the emperor Frederic III., who raised the dignity of his house by A. an archduchy. After the death of Ladislaw and of his own brother, Albrecht', Frederic came into the undivided possession of the archduchy (1464).
His son, Maximilian I., by marrying Maria, daughter of Charles the Bold, acquired (1477) the Netherlands. Becoming emperor on the death of his father (1493), he ceded the government of the Netherlands to his son Philip. Under Maximilian, Tyrol fell again to the chief branch of the house of A., several districts were acquired from Bavaria, and fresh claims were established on Hungary and Bohemia. The court of Vienna began to be the seat of German art and science. The marriage of the emperor's son Philip with Johanna of Spain set the .house of Hapsburg on the throne of Spain and the Indies. Philip died in 1506, and on the death of Maximilian I., in 1519, Philip's son, Charles I. of Spain, was elected German emperor as Charles V. (q.v.). Charles resigned by treaty all the German possessions, except the Netherlands, to his brother, Ferdinand I. (q.v.).