The March of Styria (German: Steiermark) is originally broken off the Duchy of Carinthia before 970 as a buffer zone against the Magyars.

Originally it is known as the Carantanian march (marchia Carantana), after the former Slavic principality of Carantania, a predecessor of the Carinthian duchy.

During the 11th century it evolvei to be called Styria, so named for the town of Steyr, the residence of the margraves.The area is formerly part of the larger March of Carinthia, itself a frontier march of the Duchy of Bavaria.

In 976 Emperor Otto II separates Carinthia from the Bavarian stem duchy and raises it to the status of a duchy in its own right.

The adjacent territory in the east up to the Mur, Mürz and Enns rivers, that had been annexed by King Otto I after the 955 Battle of Lechfeld, is similarly converted into the marchia Carantana of the new Carinthian duchy.The first margraves of Styria appear in the early 11th century.

The dynasty ruling from 1056 is called the Otakars.

Margrave Leopold the Strong (1122–1129) and his son Ottokar III (1129–1164) acquire large territories along the Savinja river down to the Windic March and move their residence to Graz.

In 1180, the march is converted into the Duchy of Styria.