The region came under Carolingian influence in 788, being gradually organized as a county, that was originally placed under Friulian jurisdiction (828), but later transferred to East Francia and reorganized into a frontier march.

[1][2][3] Before the coming of the Romans (c. 200 BC), the Taurisci dwelt in the north of Carniola, the Pannonians in the south-east, the Iapodes or Carni, a Celtic tribe, in the south-west.

Initially, the margraviate was bordered by Carinthia and Styria (elevated to a duchy in 1156) to the north, the Croatia and Slavonia to the east, Istria and Dalmatia to the south, and Friuli, Gorizia, Udine and Gradisca to the west.

The Carniolan lands were bound informally to the other marches of the southeast of the Empire in what has been termed the "Austrian complex" because of the supremacy which Austria quickly obtained over the others and the way in which they tended to follow her.

Nevertheless, its status as the most southeasterly of the marches helped it retain its marcher privileges well into the thirteenth century and long after the other regions, especially Friuli, had lost theirs.

After the extinction of the Thuringian counts of Weimar upon the death of Margrave Ulric II in 1112 (he may have resigned his march in 1107 or 1108), the patriarchate took over the governing of the territory, against the resistance of the Rhenish House of Sponheim, dukes of Carinthia from 1122.

[9] In 1245, Patriarch Berthold gave Carniola to the Babenberg duke Frederick II of Austria, husband of Agnes of Merania, with royal consent.

Ottokar likewise had acquired the princeless Duchy of Austria with Styria, and upon Ulric's death in 1269 he united Carinthia and Carniola to his Crown.

Ottokar refused, but was eventually put under Imperial ban in 1276 and forced to cede the lands, only retaining his Kingdom of Bohemia with Moravia.

Rudolph enfeoffed Carniola to his sons Albert and Rudolf II in 1282 after a meeting in Augsburg, but instead he leased the margraviate to his ally Count Meinhard of Tyrol, whom he appointed Duke of Carinthia from 1286.