The Duchy of Thuringia was an eastern frontier march of the Merovingian kingdom of Austrasia, established about 631 by King Dagobert I after his troops had been defeated by the forces of the Slavic confederation of Samo at the Battle of Wogastisburg. It was recreated in the Carolingian Empire and its dukes appointed by the king until it was absorbed by the Saxon dukes in 908. From about 1111/12 the territory was ruled by the Landgraves of Thuringia as Princes of the Holy Roman Empire.

The former kingdom of the Thuringii arose during the Migration Period after the decline of the Hunnic Empire in Central Europe in the mid 5th century, culminating in their defeat in the 454 Battle of Nedao. With Bisinus a first Thuringian king is documented about 500, who ruled over extended estates that stretched beyond the Main River in the south. His son and successor Hermanafrid married Amalaberga, a niece of the Ostrogoth king Theoderic the Great, thereby hedging the threat of incursions by the Merovingian Franks in the west. However, when King Theoderic died in 526, they took the occasion to invade the Thuringian lands and finally carried off the victory in a 531 battle on the Unstrut River. King Theuderic of Rheims had Hermanafrid trapped in Zülpich (Tolbiacum) where the last Thuringian king was killed. His niece Princess Radegund was kidnapped by King Chlothar I and died in exile in 586.

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