It was created by Emperor Frederick Barbarossa in 1180 when he raised the March of Styria to a duchy of equal rank with neighbouring Carinthia and Bavaria, after the fall of the Bavarian Duke Henry the Lion earlier that year.

As Ottokar had no issue, he in 1186 signed the Georgenberg Pact with the mighty House of Babenberg, rulers of Austria since 976, after which both duchies should in perpetuity be ruled in personal union.

Rudolph finally defeated Ottokar at the 1278 Battle on the Marchfeld, seized Austria and Styria and granted them to his sons Albert I and Rudolf II.

The duchy was, however, separated from Austria by the 1379 Treaty of Neuberg, after which Styria, Carinthia, and Carniola formed the Inner Austrian territory ruled by the descendants of Leopold III of the Leopoldian line, who took their residence at Graz.

The Turks made incursions into Styria nearly twenty times; churches, monasteries, cities, and villages were destroyed and plundered, while the population was either killed or carried away into slavery.

In the course of the Austro-Hungarian Compromise of 1867 (Ausgleich), the duchy was assigned as a crown land for the Cisleithanian part of Austria-Hungary, while along with the rise of nationalism the conflict between the German and Slovene population intensified.

[1] In 1910 the population of Styria included:[2] Otakars House of Babenberg Přemyslids Árpád dynasty Leopoldian line See List of rulers of Austria.