Duchy of Thuringia

Duchy (Landgraviate) of Thuringia Herzogtum (Landgrafschaft) Thüringen
631/32–1440
The Ludowingian lion barry (presumed banner of arms) Coat of arms of Landgrave Albert II, 1265
Status	Frankish duchy, then State of the Holy Roman Empire
Capital	Erfurt
Religion	Roman Catholicism
Government	Feudal Duchy
Historical era	Middle Ages
• Frankish invasion	c. 531
• Duchy established	631/32
• Re-established as Landgraviate	1111/12
• Comital line extinct	1247
• Split off Hesse	1264
• To Saxony	1440
• Division of Altenburg	1445
Preceded by Succeeded by Thuringii Landgraviate of Hesse Electorate of Saxony

The Duchy of Thuringia was an eastern frontier march of the Merovingian kingdom of Austrasia,^[1] 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 were 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. When Frederick IV, the last independent ruler of Thuringia died in 1440, the territory passed to his nephew, the Saxon elector Frederick II.