The first nucleus round which the present dominions of the house of Austria gradually accumulated was the mark which lay along the south bank of the Danube, east of the river Enns, founded about A.D. 800 as a defence for the Frankish kingdom against the Slavs. Although its total length from east to west was only about 60 m., it was associated in the popular mind with a large and almost unbroken tract of land in the east of Europe. This fact, together with the position of the mark with regard to Germany in general and to Bavaria in particular, accounts for the name _Österreich_ (Austria), _i.e._ east empire or realm, a word first used in a charter of 996, where the phrase _in regione vulgari nomine Ostarrichi_ occurs. The development of this small mark into the Austro-Hungarian monarchy was a slow and gradual process, and falls into two main divisions, which almost coincide with the periods during which the dynasties of Babenberg and Habsburg have respectively ruled the land. The energies of the house of Babenberg were chiefly spent in enlarging the area and strengthening the position of the mark itself, and when this was done the house of Habsburg set itself with remarkable perseverance and marvellous success to extend its rule over neighbouring territories. The many vicissitudes which have attended this development have not, however, altered the European position of Austria, which has remained the same for over a thousand years. Standing sentinel over the valley of the middle Danube, and barring the advance of the Slavs on Germany, Austria, whether mark, duchy or empire, has always been the meeting-place of the Teuton and the Slav. It is this fact which gives it a unique interest and importance in the history of Europe, and which unites the ideas of the Germans to-day with those of Charlemagne and Otto the Great.
The southern part of the country now called Austria was inhabited before the opening of the Christian era by the Taurisci, a Celtic tribe, who were subsequently called the Norici, and who were conquered by the Romans about 14 B.C. Their land was afterwards included in the provinces of Pannonia and Noricum, and under Roman rule, Vindobona, the modern Vienna, became a place of some importance. The part of the country north of the Danube was peopled by the Marcomanni and the Quadi, and both of these tribes were frequently at war with the Romans, especially during the reign of the emperor Marcus Aurelius, who died at Vindobona in A.D. 180 when campaigning against them. Christianity and civilization obtained entrance into the land, but the increasing weakness of the Roman empire opened the country to the inroads of the barbarians, and during the period of the great migrations it was ravaged in quick succession by a number of these tribes, prominent among whom were the Huns. The lands on both banks of the river shared the same fate, due probably to the fact to which Gibbon has drawn attention, that at this period the Danube was frequently frozen over. About 590 the district was settled by the Slovenes, or Corutanes, a Slavonic people, who formed part of the kingdom of Samo, and were afterwards included in the extensive kingdom of the Avars. The Franks claimed some authority over this people, and probably some of the princes of the Slovenes had recognized this claim, but it could not be regarded as serious while the Avars were in possession of the land. In 791 Charlemagne, after he had established his authority over the _Bajuvarii_ or Bavarians, crossed the river Enns, and moved against the Avars. This attack was followed by campaigns on the part of his lieutenants, and in 805 the Avars were finally subdued, and their land incorporated with the Frankish empire. [Sidenote: Establishment of the East Mark.] This step brought the later Austria definitely under the rule of the Franks, and during the struggle Charlemagne erected a mark, called the East Mark, to defend the eastern border of his empire. A series of margraves ruled this small district from 799 to 907, but as the Frankish empire grew weaker, the mark suffered more and more from the ravages of its eastern neighbours. During the 9th century the Frankish supremacy vanished, and the mark was overrun by the Moravians, and then by the Magyars, or Hungarians, who destroyed the few remaining traces of Frankish influence.