The Romans opened up the country by an extensive system of roads. Among the Roman towns along the Danube, Carnuntum (near Hainburg) took precedence over Vindobona (Vienna), while Lauriacum (Lorch; near the confluence of the Enns River and the Danube) belonged to a later period. Roman municipalities (municipia) also grew up at Brigantium (Bregenz), Juvavum (Salzburg), Ovilava (Wels), Virunum (near Klagenfurt), Teurnia (near Spittal), and Flavia Solva (near Leibnitz). North of the Danube the Germanic tribes of the Naristi, Marcomanni, and Quadi settled. Their invasions in 166–180 ce arrested the peaceful development of the provinces, and, even after their repulse by the emperor Marcus Aurelius, the country could not regain its former prosperity. In the 3rd century the Roman frontier defenses began to be hard-pressed by invasions from the Alemanni. Finally, in the 5th century, heavy attacks by the Huns and the eastern Germans put an end to the Roman provincial defense system on the Danube.
There is archaeological evidence of a Christian cult in this area from the 4th century, and the biography of St. Severinus by Eugippius constitutes a unique literary source for the dramatic events of the second half of the 5th century. At that time several Germanic tribes (the Rugii, Goths, Heruli, and, later, Langobardi) settled on Austrian territory. In 488 part of the harassed Norican population was forced to withdraw to Italy. Early Middle Ages Germanic and Slavic settlement
Following the departure of the Langobardi to Italy (568), further development was determined by the Bavarians in a struggle with the Slavs, who were invading from the east, and by the Alemanni, who settled in what is now Vorarlberg. The Bavarians were under the political influence of the Franks, whereas the Slavs had Avar rulers. At the time of their greatest expansion, the Slavs had penetrated as far as Niederösterreich (Lower Austria), Steiermark (Styria), Kärnten (Carinthia), and eastern Tirol. After 624 the western Slavs rose against the Avars under the leadership of the Frankish merchant Samo, whose short-lived rule may also have extended over the territories of the eastern Alps. About 700 the Bavarian lands again bordered on Avar territory, with the lower course of the Enns forming the approximate frontier. On the death of the Frankish king Dagobert I (639), the Bavarian dukes from the house of Agilolfing became virtually independent.
Christianity had survived only here and there among the remnants of the Roman population when, about 600 and again about 700, Christian missionaries from the west became active, with the support of the Bavarian dukes. At the end of the 7th century, St. Rupert, who came from the Rhine, founded the church of Salzburg. When they were threatened once more by the Avars, the Alpine Slavs (Karantani) placed themselves (before 750) under the protection of the Bavarians, whose mission was extended to them. At the same time, Bavarian settlers penetrated into the valleys of Kärnten and Steiermark. Charlemagne, emperor of the neighbouring Franks, however, deposed the Bavarian duke Tassilo III, wiping out the Bavarian dukedom for a century. During the following years (791–796), Charlemagne led a number of attacks against the Avars and destroyed their dominion. Surviving Avars were made to settle in the eastern part of Lower Austria between the rivers of Fischa and Leitha, where they soon disappeared from history, most probably mixing with the native population.
As was the usual Frankish practice, border provinces (Marken, or marches) were instituted in the newly won southeastern territories. The Avar March on the Danube and Lower and Upper Pannonia and Karantania were to form a border fortification, but this arrangement soon became less effective because of frequent disagreements among the nobility. To that unrest was added a threat from the Bulgarians and from the rulers of Great Moravia (see Moravia). Nevertheless, the process of Germanization and Christianization continued, during the course of which the churches of Salzburg and Passau came into conflict with the eastern mission, which was led by the Slav apostles Cyril and Methodius. The Frankish kingdom richly endowed the church and nobility with new lands, which came to be settled by Bavarian and Frankish farmers.
In 881 the beginning of incursions by the Magyars led to a first clash near Vienna. By 906 they had destroyed Great Moravia, and in 907 near Pressburg (Bratislava, Slvk.) the Magyars defeated a large Bavarian army that had tried to win back lost territory. Liutpold of Bavaria as well as Theotmar, the archbishop of Salzburg, were killed in battle. The Lower Austrian territories as far as the Enns River, and Steiermark as far as the Koralpe massif, fell under Magyar domination. Nevertheless, a certain continuity of German-Slav settlement was maintained so that, after the victory of the German king Otto I (later Holy Roman emperor) in 955 and the further repulse of the Magyars in the 960s, a fresh start could be made. (See also Germany: History; Holy Roman Empire.) Early Babenberg period
The first mention of a ruler in the regained territories east of the Enns is of Burchard, who probably was count (burgrave) of Regensburg. It appears that he lost his office as a result of his championship of Henry II the Quarrelsome, duke of Bavaria. In 976 his successor, Leopold I of the house of Babenberg, was installed in office. Under Leopold’s rule the eastern frontier was extended to the Vienna Woods after a war with the Magyars. Under his successor, Henry I, the country around Vienna itself must have come into German hands. New marches were also created in what were later known as Carniola and Steiermark.
Wars against Hungarians and Moravians occupied the reign (1018–55) of Margrave (a count who ruled over a march) Adalbert. Parts of Lower Austria on both sides of the Danube were lost temporarily; after they were retaken, they became the so-called Neumark (New March), which for some time enjoyed independence—as did the Bohemian March to the north of the Babenberg territories. The position of the Babenbergs was at that time still a modest one; their territorial rights were no greater than those of other leading noble families. Their power within their own official sphere was further diminished by ecclesiastical immunities (Passau in particular but also Salzburg, Regensburg, and Freising), with numerous monasteries owning large territories as well.
Austria was repeatedly drawn into the disputes of the Investiture Controversy, in which Pope Gregory VII and King Henry IV (later Holy Roman emperor) fought for control of the church in Germany. In 1075 Margrave Ernest, who had regained the Neumark and the Bohemian March for his family, was killed in the Battle of the Unstrut, fighting on the side of Henry IV against the rebellious Saxons. Altmann, bishop of Passau, a leader of church reform and a champion of Gregory VII, influenced the next Babenberg margrave, Leopold II, to abandon Henry’s cause. As a result, Henry roused the Bohemian duke Vratislav II against him, and in 1082 Leopold II was defeated near Mailberg, his territories north of the Danube devastated. The Babenbergs, however, managed to survive these setbacks. Meanwhile, the cause of church reform gained ground, with its centres in the newly founded monasteries of Göttweig, Lambach, and, in Steiermark, Admont.